Astrophysics

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New submissions for Wed, 1 May 24

[1]  arXiv:2404.18983 [pdf, other]

Title: Evidence for Plasmoid-mediated Magnetic Reconnection during a Small-scale Flare in the Partially Ionized Low Solar Atmosphere

Authors: Guanchong Cheng, Lei Ni, Zehao Tang, Yajie Chen, Yuhao Chen, Jialiang Hu, Jun Lin

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

Magnetic reconnection plays a crucial role in the energy release process for different kinds of solar eruptions and activities. The rapid solar eruption requires a fast reconnection model. Plasmoid instability in the reconnecting current sheets is one of the most acceptable fast reconnection mechanisms for explaining the explosive events in the magnetohydrodynamics (MHD) scale, which is also a potential bridge between the macroscopic MHD reconnection process and microscale dissipations. Plenty of high resolution observations indicate that the plasmoid-like structures exist in the high temperature solar corona, but such evidences are very rare in the lower solar atmosphere with partially ionized plasmas. Utilizing joint observations from the Goode Solar Telescope (GST) and the Solar Dynamics Observatory (SDO), we discovered a small-scale eruptive phenomenon in NOAA AR 13085, characterized by clear reconnection cusp structures, supported by Nonlinear Force-Free Field (NLFFF) extrapolation results. The plasmoid-like structures with a size about 150 km were observed to be ejected downward from the current sheet at a maximum velocity of 24 km$\cdot$s$^{-1}$ in the H$\alpha$ line wing images, followed by enhanced emissions at around the post flare loop region in multiple wave lengths. Our 2.5D high-resolution MHD simulations further reproduced such a phenomenon and revealed reconnection fine structures. These results provide comprehensive evidences for the plasmoid mediated reconnection in partially ionized plasmas, and suggest an unified reconnection model for solar flares with different length scales from the lower chromosphere to corona.

[2]  arXiv:2404.18991 [pdf, other]

Title: A dusty proto-cluster surrounding the binary galaxy HerBS-70 at $z = 2.3$

Authors: Tom J.L.C. Bakx, S. Berta, H. Dannerbauer, P. Cox, K.M. Butler, M. Hagimoto, D.H. Hughes, D.A. Riechers, P.P. van der Werf, C. Yang, A.J. Baker, A. Beelen, G.J. Bendo, E. Borsato, V. Buat, A.R. Cooray, L. Dunne, S. Dye, S. Eales, R. Gavazzi, A.I. Harris, D. Ismail, R.J. Ivison, B. Jones, M. Krips, M.D. Lehnert, L. Marchetti, H. Messias, M. Negrello, R. Neri, A. Omont, I. Perez-Fournon, A. Nanni, N. Chartab, S. Serjeant, F. Stanley, Y. Tamura, S. A. Urquhart, C. Vlahakis, A. Weiß, A. J. Young

Comments: 19 pages, 13 figures, accepted for publication in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We report on deep SCUBA-2 observations at 850$\mu$m and NOEMA spectroscopic measurements at 2 mm of the environment surrounding the luminous, massive ($M_{*} \approx 2 \times 10^{11}$ M$_{\odot}$) Herschel-selected source HerBS-70. This source was revealed by previous NOEMA observations to be a binary system of dusty star-forming galaxies at $z= 2.3$, with the East component (HerBS-70E) hosting an Active Galactic Nucleus (AGN). The SCUBA-2 observations detected, in addition to the binary system, twenty-one sources at $> 3.5 \sigma$ over an area of $\sim 25$ square comoving Mpc with a sensitivity of $\sigma_{850} = 0.75$ mJy. The surface density of continuum sources around HerBS-70 is three times higher than for field galaxies. The NOEMA spectroscopic measurements confirm the protocluster membership of three of the nine brightest sources through their CO(4 - 3) line emission, yielding a volume density 36 times higher than for field galaxies. All five confirmed sub-mm galaxies in the HerBS-70 system have relatively short gas depletion times ($80 - 500$ Myr), indicating the onset of quenching for this protocluster core due to the depletion of gas. The dark matter halo mass of the HerBS-70 system is estimated around $5 \times{} 10^{13}$ M$_{\odot}$, with a projected current-day mass of $10^{15}$ M$_{\odot}$, similar to the local Virgo and Coma clusters. These observations support the claim that DSFGs, in particular the ones with observed multiplicity, can trace cosmic overdensities.

[3]  arXiv:2404.18997 [pdf, other]

Title: Planet Hunters TESS V: a planetary system around a binary star, including a mini-Neptune in the habitable zone

Authors: Nora L. Eisner, Samuel K. Grunblatt, Oscar Barragán, Thea H. Faridani, Chris Lintott, Suzanne Aigrain, Cole Johnston, Ian R.Mason, Keivan G. Stassun, Megan Bedell, Andrew W. Boyle, David R. Ciardi, Catherine A. Clark, Guillaume Hebrard, David W. Hogg, Steve B. Howell, Baptiste Klein, Joe Llama, Joshua N. Winn, Lily L. Zhao, Joseph M. Akana Murphy, Corey Beard, Casey L. Brinkman, Ashley Chontos, Pia Cortes-Zuleta, Xavier Delfosse, Steven Giacalone, Emily A. Gilbert, Neda Heidari, Rae Holcomb, Jon M. Jenkins, Flavien Kiefer, Jack Lubin, Eder Martioli, Alex S. Polanski, Nicholas Saunders, Sara Seager, Avi Shporer, Dakotah Tyler, Judah Van Zandt, Safaa Alhassan, Daval J. Amratlal, Lais I. Antonel, Simon L. S. Bentzen, Milton K. D. Bosch, David Bundy, Itayi Chitsiga, Jérôme F. Delaunay, et al. (16 additional authors not shown)

Comments: 24 pages, 16 figures, 4 tables

Journal-ref: Published in AJ, 2024

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

We report on the discovery and validation of a transiting long-period mini-Neptune orbiting a bright (V = 9.0 mag) G dwarf (TOI 4633; R = 1.05 RSun, M = 1.10 MSun). The planet was identified in data from the Transiting Exoplanet Survey Satellite by citizen scientists taking part in the Planet Hunters TESS project. Modeling of the transit events yields an orbital period of 271.9445 +/- 0.0040 days and radius of 3.2 +/- 0.20 REarth. The Earth-like orbital period and an incident flux of 1.56 +/- 0.2 places it in the optimistic habitable zone around the star. Doppler spectroscopy of the system allowed us to place an upper mass limit on the transiting planet and revealed a non-transiting planet candidate in the system with a period of 34.15 +/- 0.15 days. Furthermore, the combination of archival data dating back to 1905 with new high angular resolution imaging revealed a stellar companion orbiting the primary star with an orbital period of around 230 years and an eccentricity of about 0.9. The long period of the transiting planet, combined with the high eccentricity and close approach of the companion star makes this a valuable system for testing the formation and stability of planets in binary systems.

[4]  arXiv:2404.18998 [pdf, other]

Title: Intergalactic Lyman-$α$ haloes before reionization are detectable with JWST

Authors: Hamsa Padmanabhan (Geneva), Abraham Loeb (Harvard)

Comments: 13 pages, 3 figures, 2 tables

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)

The $James \ Webb \ Space \ Telescope \ (JWST)$ recently reported a large population of UV luminous galaxies at high redshifts, $ z > 10$, as well as Lyman-$\alpha$ emitting (LAE) galaxies out to $z \sim 11$. We use the observed UV luminosities along with a data-driven approach at lower redshifts to place constraints on the observability of the intergalactic Lyman-$\alpha$ intensity, scattered in the form of Loeb-Rybicki haloes, during the pre-reionization and reionization epochs ($z \sim 9-16$). We forecast the sensitivity and resolution required to detect these intergalactic haloes, finding that individual haloes with LAE luminosities $> 10^{43}$ ergs/s are detectable at a few sigma level at $z \lesssim 11$, while stacking of $\sim 10$ haloes is expected to result in detections out to $z \sim 16$. Finding these haloes is expected to shed light on the neutral intergalactic hydrogen during cosmic reionization.

[5]  arXiv:2404.18999 [pdf, other]

Title: CO Observations of Early-mid Stage Major-mergers in MaNGA Survey

Authors: Qingzheng Yu, Taotao Fang, Cong Kevin Xu, Shuai Feng, Siyi Feng, Yu Gao, Xue-Jian Jiang, Ute Lisenfeld

Comments: 25 pages, 12 figures, 5 tables, accepted for publication in ApJS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We present a study of the molecular gas in early-mid stage major-mergers, with a sample of 43 major-merger galaxy pairs selected from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey and a control sample of 195 isolated galaxies selected from the xCOLD GASS survey. Adopting kinematic asymmetry as a new effective indicator to describe the merger stage, we aim to study the role of molecular gas in the merger-induced star formation enhancement along the merger sequence of galaxy pairs. We obtain the molecular gas properties from CO observations with the James Clerk Maxwell Telescope (JCMT), Institut de Radioastronomie Milimetrique (IRAM) 30-m telescope, and the MASCOT survey. Using these data, we investigate the differences in molecular gas fraction ($f_{\rm H_{2}}$), star formation rate (SFR), star formation efficiency (SFE), molecular-to-atomic gas ratio ($M_{\rm H_{2}}/M_{\rm HI}$), total gas fraction ($f_{\rm gas}$), and the star formation efficiency of total gas (${\rm SFE_{gas}}$) between the pair and control samples. In the full pair sample, our results suggest the $f_{\rm H_{2}}$ of paired galaxies is significantly enhanced, while the SFE is comparable to that of isolated galaxies. We detect significantly increased $f_{\rm H_{2}}$ and $M_{\rm H_{2}}/M_{\rm HI}$ in paired galaxies at the pericenter stage, indicating an accelerated transition from atomic gas to molecular gas due to interactions. Our results indicate that the elevation of $f_{\rm H_{2}}$ plays a major role in the enhancement of global SFR in paired galaxies at the pericenter stage, while the contribution of enhanced SFE in specific regions requires further explorations through spatially resolved observations of a larger sample spanning a wide range of merger stages.

[6]  arXiv:2404.19001 [pdf, other]

Title: Gamma-ray Emission from a Young Star Cluster in the Star-Forming Region RCW 38

Authors: Paarmita Pandey, Laura A. Lopez, Anna L. Rosen, Todd A. Thompson, Tim Linden, Ian Blackstone, Lachlan Lancaster

Comments: Submitted to ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We report the detection of gamma-ray emission near the young Milky Way star cluster ($\approx$ 0.5 Myr old) in the star-forming region RCW 38. Using 15 years of data from the Fermi-LAT, we find a significant ($ \sigma > 22$) detection coincident with the cluster, producing a total $\gamma$-ray luminosity of $L_{\gamma} = (2.66\pm 0.92) \times 10^{34}$ erg s$^{-1}$ adopting a power-law spectral model ($\Gamma = 2.34\pm0.04$) in the 0.1 $-$ 500 GeV band. We estimate the total wind power to be $7 \times 10^{36}$ erg s$^{-1}$, corresponding to a CR acceleration efficiency of $\eta_{\rm CR} \simeq 0.4$ for a diffusion coefficient consistent with the local interstellar medium of $D = 10^{28}$ cm$^{2}$ s$^{-1}$. Alternatively, the $\gamma$-ray luminosity could also account for a lower acceleration efficiency of 0.1 if the diffusion coefficient in the star-forming region is smaller, $D\simeq 2.5\times10^{27}\,{\rm cm^2\,\,s^{-1}}$. We compare the hot-gas pressure from Chandra X-ray analysis to the CR pressure and find the former is four orders of magnitude greater, suggesting that the CR pressure is not dynamically important relative to the stellar wind feedback. As RCW 38 is too young for supernovae to have occurred, the high CR acceleration efficiency in RCW 38 demonstrates that stellar winds may be an important source of Galactic cosmic rays.

[7]  arXiv:2404.19002 [pdf, other]

Title: Associating LOFAR Galactic Faraday structures with the warm neutral medium

Authors: F. Boulanger, C. Gry, E. B. Jenkins, A. Bracco, A. Erceg, V. Jelić, L. Turić

Comments: Accepted for publication in A&A

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Faraday tomography observations with the Low Frequency Array (LOFAR) have unveiled a remarkable network of structures in polarized synchrotron emission at high Galactic latitudes. The observed correlation between LOFAR structures, dust polarization, and HI emission suggests a connection to the neutral interstellar medium (ISM). We investigated this relationship by estimating the rotation measure (RM) of the warm neutral (partially ionized) medium (WNM) in the local ISM. Our work combines UV spectroscopy from FUSE and dust polarization observations from \Planck\ with LOFAR data. We derived electron column densities from UV absorption spectra toward nine background stars, within the field of published data from the LOFAR two-meter sky survey. The associated RMs were estimated using a local magnetic field model fitted to the dust polarization data of \Planck. A comparison with Faraday spectra at the position of the stars suggests that LOFAR structures delineate a slab of magnetized WNM and synchrotron emission, located ahead of the bulk of the warm ionized medium. This conclusion establishes an astrophysical framework for exploring the link between Faraday structures and the dynamics of the magnetized multiphase ISM. It will be possible to test it on a larger sample of stars when maps from the full northern sky survey of LOFAR become available.

[8]  arXiv:2404.19003 [pdf, other]

Title: Implications on star-formation-rate indicators from HII regions and diffuse ionised gas in the M101 Group

Authors: A. E. Watkins, J. C. Mihos, P. Harding, R. Garner III

Comments: 17 pages, 12 figures, accepted for publication in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We examine the connection between diffuse ionised gas (DIG), HII regions, and field O and B stars in the nearby spiral M101 and its dwarf companion NGC 5474 using ultra-deep H$\alpha$ narrow-band imaging and archival GALEX UV imaging. We find a strong correlation between DIG H$\alpha$ surface brightness and the incident ionising flux leaked from the nearby HII regions, which we reproduce well using simple Cloudy simulations. While we also find a strong correlation between H$\alpha$ and co-spatial FUV surface brightness in DIG, the extinction-corrected integrated UV colours in these regions imply stellar populations too old to produce the necessary ionising photon flux. Combined, this suggests that HII region leakage, not field OB stars, is the primary source of DIG in the M101 Group. Corroborating this interpretation, we find systematic disagreement between the H$\alpha$- and FUV-derived star formation rates (SFRs) in the DIG, with SFR$_{{\rm H}\alpha} < $SFR$_{\rm FUV}$ everywhere. Within HII regions, we find a constant SFR ratio of 0.44 to a limit of $\sim10^{-5}$ M$_{\odot}$~yr$^{-1}$. This result is in tension with other studies of star formation in spiral galaxies, which typically show a declining SFR$_{{\rm H}\alpha}/$SFR$_{\rm FUV}$ ratio at low SFR. We reproduce such trends only when considering spatially averaged photometry that mixes HII regions, DIG, and regions lacking H$\alpha$ entirely, suggesting that the declining trends found in other galaxies may result purely from the relative fraction of diffuse flux, leaky compact HII regions, and non-ionising FUV-emitting stellar populations in different regions within the galaxy.

[9]  arXiv:2404.19006 [pdf, other]

Title: SN 2024ggi in NGC 3621: Rising Ionization in a Nearby, CSM-Interacting Type II Supernova

Authors: W. V. Jacobson-Galán, K. W. Davis, C. D. Kilpatrick, L. Dessart, R. Margutti, R. Chornock, R. J. Foley, P. Arunachalam, K. Auchettl, C. R. Bom, R. Cartier, D. A. Coulter, G. Dimitriadis, D. Dickinson, M. R. Drout, A. T. Gagliano, C. Gall, B. Garretson, L. Izzo, D. O. Jones, N. LeBaron, H.-Y. Miao, D. Milisavljevic, Y.-C. Pan, A. Rest, C. Rojas-Bravo, A. Santos, H. Sears, B. M. Subrayan, K. Taggart, S. Tinyanont

Comments: 15 pages, 7 figures. Submitted to ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)

We present UV/optical/NIR observations and modeling of supernova (SN) 2024ggi, a type II supernova (SN II) located in NGC 3621 at 7.2 Mpc. Early-time ("flash") spectroscopy of SN 2024ggi within +0.8 days of discovery shows emission lines of H I, He I, C III, and N III with a narrow core and broad, symmetric wings (i.e., IIn-like) arising from the photoionized, optically-thick, unshocked circumstellar material (CSM) that surrounded the progenitor star at shock breakout. By the next spectral epoch at +1.5 days, SN 2024ggi showed a rise in ionization as emission lines of He II, C IV, N IV/V and O V became visible. This phenomenon is temporally consistent with a blueward shift in the UV/optical colors, both likely the result of shock breakout in an extended, dense CSM. The IIn-like features in SN 2024ggi persist on a timescale of $t_{\rm IIn} = 3.8 \pm 1.6$ days at which time a reduction in CSM density allows the detection of Doppler broadened features from the fastest SN material. SN 2024ggi has peak UV/optical absolute magnitudes of $M_{\rm w2} = -18.7$ mag and $M_{\rm g} = -18.1$ mag that are consistent with the known population of CSM-interacting SNe II. Comparison of SN 2024ggi with a grid of radiation hydrodynamics and non-local thermodynamic equilibrium (nLTE) radiative-transfer simulations suggests a progenitor mass-loss rate of $\dot{M} = 10^{-2}$M$_{\odot}$ yr$^{-1}$ ($v_w$ = 50 km/s), confined to a distance of $r < 5\times 10^{14}$ cm. Assuming a wind velocity of $v_w$ = 50 km/s, the progenitor star underwent an enhanced mass-loss episode in the last ~3 years before explosion.

[10]  arXiv:2404.19010 [pdf, other]

Title: X-ray View of Little Red Dots: Do They Host Supermassive Black Holes?

Authors: Tonima Tasnim Ananna, Ákos Bogdán, Orsolya E. Kovács, Priyamvada Natarajan, Ryan C. Hickox

Comments: Submitted to ApJL

Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

The discovery of Little Red Dots (LRDs) -- a population of compact, high-redshift, dust-reddened galaxies -- is one of the most surprising results from \textit{JWST}. However, the nature of LRDs is still debated: some studies suggest that these galaxies host accreting supermassive black holes (SMBHs), while others conclude that the near-infrared emission primarily originates from intense star formation. In this work, we utilize ultra-deep \textit{Chandra} observations and study LRDs residing behind the lensing galaxy cluster, Abell~2744. We probe the X-ray emission from individual galaxies but find that they remain undetected and provide SMBH mass upper limits of $\lesssim(1.5-16)\times10^{6}~\rm{M_{\odot}}$ assuming Eddington limited accretion. To increase the signal-to-noise ratios, we conduct a stacking analysis of the full sample with a total lensed exposure time of $\approx87$~Ms. We also bin the galaxies based on their stellar mass, lensing magnification, and detected broad-line H$\alpha$ emission. All but one stacked sample remains undetected with SMBH mass upper limits of $\lesssim2.5\times10^{6}~\rm{M_{\odot}}$. We obtain a tentative, $\approx2.6\sigma$ detection for LRDs exhibiting broad-line H$\alpha$ emission. Taking this detection at face value, the inferred mean SMBH mass is $\approx3.2\times10^{6}~\rm{M_{\odot}}$ assuming Eddington-limited accretion, about 1.5 orders of magnitude lower than that inferred from \textit{JWST} data. Our results imply that LRDs do not host over-massive SMBHs and/or accrete at a few percent of their Eddington limit. The significant discrepancy between the \textit{JWST} and \textit{Chandra} data hints that the scaling relations used to infer the SMBH mass from the H$\alpha$ line and virial relations may not be applicable for high-redshift LRDs.

[11]  arXiv:2404.19017 [pdf, other]

Title: SN 1054 as a Pulsar-Driven Supernova: Implications for the Crab Pulsar and Remnant Evolution

Authors: Conor M. B. Omand, Nikhil Sarin, Tea Temim

Comments: Submitted to MNRAS. Comments welcome

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

One of the most studied objects in astronomy, the Crab Nebula, is the remnant of the historical supernova SN 1054. Historical observations of the supernova imply a typical supernova luminosity, but contemporary observations of the remnant imply a low explosion energy and low ejecta kinetic energy. These observations are incompatible with a standard $^{56}$Ni-powered supernova, hinting at an an alternate power source such as circumstellar interaction or a central engine. We examine SN 1054 using a pulsar-driven supernova model, similar to those used for superluminous supernovae. The model can reproduce the luminosity and velocity of SN 1054 for an initial spin period of $\sim$ 13 ms and an initial dipole magnetic field of 10$^{14-15}$ G. We discuss the implications of these results, including the evolution of the Crab pulsar, the evolution of the remnant structure, formation of filaments, and limits on freely expanding ejecta. We discuss how our model could be tested further through potential light echo photometry and spectroscopy, as well as the modern analogues of SN 1054.

[12]  arXiv:2404.19018 [pdf, other]

Title: MAGAZ3NE: Massive, Extremely Dusty Galaxies at $z\sim2$ Lead to Photometric Overestimation of Number Densities of the Most Massive Galaxies at $3<z<4$

Authors: Ben Forrest, M. C. Cooper, Adam Muzzin, Gillian Wilson, Danilo Marchesini, Ian McConachie, Percy Gomez, Marianna Annunziatella, Z. Cemile Marsan, Joey Braspenning, Wenjun Chang, Gabriella de Lucia, Fabio Fontanot, Michaela Hirschmann, Dylan Nelson, Annalisa Pillepich, Joop Schaye, Stephanie M. Urbano Stawinski, Mauro Stefanon, Lizhi Xie

Comments: Submitted to ApJ. Comments welcome!

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We present rest-frame optical spectra from Keck/MOSFIRE and Keck/NIRES of 16 candidate ultramassive galaxies targeted as part of the Massive Ancient Galaxies at $z>3$ Near-Infrared (MAGAZ3NE) Survey. These candidates were selected to have photometric redshifts $3\lesssim z_{\rm phot}<4$, photometric stellar masses log($M$/M$_\odot$)$>11.7$, and well-sampled photometric spectral energy distributions (SEDs) from the UltraVISTA and VIDEO surveys. In contrast to previous spectroscopic observations of blue star-forming and post-starburst ultramassive galaxies, candidates in this sample have very red SEDs implying significant dust attenuation, old stellar ages, and/or active galactic nuclei (AGN). Of these galaxies, eight are revealed to be heavily dust-obscured $2.0<z<2.7$ galaxies with strong emission lines, some showing broad features indicative of AGN, three are Type I AGN hosts at $z>3$, one is a $z\sim1.2$ dusty galaxy, and four galaxies do not have a confirmed spectroscopic redshift. In fact, none of the sample has |$z_{\rm spec}-z_{\rm phot}$|$<0.5$, suggesting difficulties for photometric redshift programs in fitting similarly red SEDs. The prevalence of these red interloper galaxies suggests that the number densities of high-mass galaxies are overestimated at $z\gtrsim3$ in large photometric surveys, helping to resolve the `impossibly early galaxy problem' and leading to much better agreement with cosmological galaxy simulations. A more complete spectroscopic survey of ultramassive galaxies is required to pin down the uncertainties on their number densities in the early universe.

[13]  arXiv:2404.19068 [pdf, other]

Title: Faraday tomography of LoTSS-DR2 data: II. Multi-tracer analysis in the high-latitude outer Galaxy

Authors: Ana Erceg, Vibor Jelić, Marijke Haverkorn, Andrea Bracco, Lana Ceraj, Luka Turić, Juan D. Soler

Comments: 11 pages, 10 figures; accepted for publication in A&A; data products are available at this https URL

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We conducted a follow-up study on the analysis of the LOw Frequency ARray (LOFAR) Two-metre Sky Survey (LoTSS) mosaic in the high-latitude outer Galaxy presented in the first paper of this series. Here, we focus on the search for alignment between the magnetic field traced by dust, HI filaments, starlight optical linear polarisation, and linear depolarised structures (depolarisation canals) observed in low-frequency synchrotron polarisation. This alignment was previously found in several smaller fields observed with LOFAR, offering valuable insights into the nature of the interstellar medium and the 3D spatial distribution of the diffuse ionised medium. We aim to determine whether the alignment of the interstellar medium (ISM) phases observed through multiple tracers is a common occurrence or an exception. Additionally, in areas where depolarisation canals align with the magnetic field, we use starlight polarisation to constrain the distance to the structures associated with the observed canals. We employed the Rolling Hough Transform (RHT) and projected Rayleigh statistics (PRS) to identify and quantify the alignment between the different tracers. On the scale of the whole mosaic, we did not find any evidence of a universal alignment among the three tracers. However, in one particular area, the western region (Dec between $29^\circ$ and $70^\circ$ and RA between $\mathrm{7^h44^m}$ and $\mathrm{9^h20^m}$), we do find a significant alignment between the magnetic field, depolarisation canals, and HI filaments. Based on this alignment, we used the starlight polarisation of stars with known parallax distances to estimate that the minimum distance to the structures observed by LOFAR in this region lies within the range of 200 to 240 pc. We associate these structures with the edge of the Local Bubble.

[14]  arXiv:2404.19069 [pdf, other]

Title: Capture of field stars by dark substructures

Authors: Jorge Peñarrubia, Raphaël Errani, Matthew G. Walker, Mark Gieles, Tjarda C. N. Boekholt

Comments: 21 pages. Submitted

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We use analytical and $N$-body methods to study the capture of field stars by gravitating substructures moving across a galactic environment. We find that the majority of captured stars move on temporarily-bound orbits that escape from the substructure potential after a few orbital revolutions. In numerical experiments where a substructure model is immersed in a galaxy on a circular orbit, we also find particles that remain bound to the substructure potential for indefinitely-long times. This population is absent from substructure models initially placed outside the galaxy on an eccentric orbit. We show that gravitational capture is most efficient in dwarf spheroidal galaxies (dSphs) on account of their low velocity dispersions and high stellar phase-space densities. In these galaxies `dark' sub-subhaloes which do not experience in-situ star formation may capture field stars and become visible as stellar overdensities with unusual properties: (i) they would have a large size for their luminosity, (ii) contain stellar populations indistinguishable from the host galaxy, and (iii) exhibit dark matter (DM)-dominated mass-to-light ratios. We discuss the nature of several `anomalous' stellar systems reported as star clusters in the Fornax and Eridanus II dSphs which exhibit some of these characteristics. A large population of DM sub-subhaloes with a mass function $d N/d M_\bullet\sim M_\bullet^{-\alpha}$ generates stellar substructures with a luminosity function, $d N/d M_\star\sim M_\star^{-\beta}$, where $\beta=(2\alpha+1)/3=1.6$ for $\alpha=1.9$. Detecting and characterizing these objects in dSphs would provide unprecedented constraints on the particle mass and cross section of a large range of DM particle candidates.

[15]  arXiv:2404.19086 [pdf, ps, other]

Title: On the Pair-Instability Supernova origin of J1010+2358

Authors: Ása Skúladóttir, Ioanna Koutsouridou, Irene Vanni, Anish M. Amarsi, Romain Lucchesi, Stefania Salvadori, David Aguado

Comments: Submitted to ApJ. 1 table, 4 figures, and appendix

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

The first (Pop III) stars formed only out of H and He and were likely more massive than present-day stars. Massive Pop III stars in the range 140-260 M$_\odot$ are predicted to end their lives as pair-instability supernovae (PISNe), enriching the environment with a unique abundance pattern, with high ratios of odd to even elements. Recently, the most promising candidate for a pure descendant of a zero-metallicity massive PISN (260 M$_{\odot}$) was discovered by the LAMOST survey, the star J1010+2358. However, the key elements to verify the high PISN contribution, C and Al, were missing from the analysis. To rectify this, we obtained and analyzed a high-resolution VLT/UVES spectrum, correcting for 3D and/or non-LTE effects. Our measurements of both C and Al give much higher values (~1 dex) than expected from a 260 M$_{\odot}$ PISN. Furthermore, we find significant discrepancies with the previous analysis, and therefore a much less pronounced odd-even effect. Thus, we show that J1010+2358 cannot be a pure descendant of a 260 M$_{\odot}$ PISN. Instead, we find that the best fit model consists of a 13 M$_{\odot}$ Pop II core-collapse supernova combined with a Pop III supernova. Alternative, less favoured solutions $(\chi^2/\chi^2_{\rm best}\approx2.3)$ include a 50% contribution from a 260 M$_{\odot}$ PISN, or a 40% contribution from a Pop III type Ia supernova. Ultimately, J1010+2358 is certainly a unique star giving insights into the earliest chemical enrichment. However, this star has not necessarily obtained any of its metals from a PISN. So the search continues for a concrete proof of the existence of zero-metallicity PISNe.

[16]  arXiv:2404.19101 [pdf, other]

Title: Neutral hydrogen filaments in interstellar media: Are they physical?

Authors: Ka Ho Yuen, Ka Wai Ho, Chi Yan Law, Avi Chen

Journal-ref: Rev. Mod. Plasma Phys. 8, 21 (2024)

Subjects: Astrophysics of Galaxies (astro-ph.GA); Plasma Physics (physics.plasm-ph)

The trending term "filament" is extensively used in the interstellar medium (ISM) and the star formation community, and is believed to be one of the most important objects that gauge molecular cloud and star formation. However, the physical definition of these ubiquitous, elongated, high contrast features is poorly defined and still actively debated. Despite the absence of a unified consensus, filaments are believed to be involved in many important physical processes from galaxy structure formation to the emergence of protostellar objects. Therefore, understanding how filaments form, what constrains their growth, and their general physical properties, are extremely important for theorists and observers who study the dynamics of the ISM and consequent star formations. This review serves as a collection of the community's views and develops the concept of "filaments" in the context of the ISM and star-forming clouds. Observationally, filaments are seen across the entire sky and often carry an aspect ratio of the order of hundreds. In the context of the ISM, filaments are believed to form by stretching and tearing from magnetized ISM turbulence. ISM filaments are subjected to heating and cooling phases, and are likely to be magnetically aligned. Cold clouds are formed inside ISM due to turbulence instability. This review updates the understanding of ISM filaments in the community.

[17]  arXiv:2404.19102 [pdf, other]

Title: Modelling the Track of the GD-1 Stellar Stream Inside a Host with a Fermionic Dark Matter Core-Halo Distribution

Authors: Martín F. Mestre, Carlos R. Argüelles, Daniel D. Carpintero, Valentina Crespi, Andreas Krut

Comments: Accepted for publication in A&A, 111 pages, 8 figures

Subjects: Astrophysics of Galaxies (astro-ph.GA); General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph)

Traditional studies on stellar streams typically involve phenomenological $\Lambda$CDM halos or ad hoc dark matter (DM) profiles with different degrees of triaxiality, which preclude to gain insights into the nature and mass of the DM particles. Recently, a Maximum Entropy Principle of halo formation has been applied to provide a DM halo model which incorporates the fermionic (quantum) nature of the particles, while leading to DM profiles which depend on the fermion mass. Such profiles develop a more general dense core - diluted halo morphology able to explain the Galactic rotation curve, while the degenerate fermion core can mimic the central massive black hole (BH). We attempt to model the GD-1 stellar stream using a spherical core-halo DM distribution for the host, which, at the same time, explains the dynamics of the S-cluster stars through its degenerate fermion-core with no central BH. We used two optimization algorithms in order to fit both the initial conditions of the stream orbit and the fermionic model. The stream observables are 5D phase-space data from the Gaia DR2 survey. We were able to find good fits for both the GD-1 stream and the S-stars for a family of fermionic core-halo profiles parameterized by the fermion mass. This work provides evidence that the fermionic profile is a reliable model for both the massive central object and the DM of the Galaxy. Remarkably, this model predicts a total MW mass of $2.3\times 10^{11}M_{\odot}$ which is in agreement with recent mass estimates obtained from Gaia DR3 rotation curves (Gaia RC). In summary, with one single fermionic model for the DM distribution of the MW, we obtain a good fit in three totally different distance scales of the Galaxy: $\sim 10^{-6}$ kpc (central, S-stars), $\sim14$ kpc (mid, GD-1) and $\sim 30$ kpc (boundary, Gaia RC mass estimate).

[18]  arXiv:2404.19103 [pdf, other]

Title: Tayler Instability Revisited

Authors: Valentin A. Skoutnev, Andrei M. Beloborodov

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)

Tayler instability of toroidal magnetic fields $B_\phi$ is broadly invoked as a trigger for turbulence and angular momentum transport in stars. This paper presents a systematic revision of the linear stability analysis for a rotating, magnetized, and stably stratified star. For plausible configurations of $B_\phi$, instability requires diffusive processes: viscosity, magnetic diffusivity, or thermal/compositional diffusion. Our results reveal a new physical picture, demonstrating how different diffusive effects independently trigger instability of two types of waves in the rotating star: magnetostrophic waves and inertial waves. It develops via overstability of the waves, whose growth rate sharply peaks at some characteristic wavenumbers. We determine instability conditions for each wave branch and find the characteristic wavenumbers. The results are qualitatively different for stars with magnetic Prandtl number $Pm\ll 1$ (e.g. the Sun) and $Pm\gg 1$ (e.g. protoneutron stars). The parameter dependence of unstable modes suggests a non-universal scaling of the possible Tayler-Spruit dynamo.

[19]  arXiv:2404.19107 [pdf, other]

Title: The calm before the (next) storm: no third outburst in 2019--2020, and ongoing monitoring of the transient AGN IC 3599

Authors: Dirk Grupe (1), S. Komossa (2), Salem Wolsing (1) ((1) Northern Kentucky University, (2) Max-Planck-Institut fuer Radio-Astronomie)

Comments: Accepted for publication in the Astrophysical Journal, 25 pages, 11 Figures, 7 Tables

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)

We report on follow-up observations of the Seyfert 1.9 galaxy IC 3599 with the NASA Neil Gehrels Swift mission. The detection of a second X-ray outburst in 2010 by Swift after the first discovery of a bright X-ray outburst in 1990 by ROSAT led to the suggestion of two very different explanations: The first one assumed that IC 3599 exhibits outbursts due to repeated partial tidal stripping of a star, predicting another outburst of IC 3599 in 2019/2020. The second, alternative scenario assumed that the event observed in X-rays is due to an accretion disk instability which would suggest a much longer period between the large outbursts. Our continued monitoring campaign by Swift allowed us to test the first scenario which predicted a repetition of high amplitude flaring activity in 2019/2020. We do not find any evidence of dramatic flaring activity with factors of 100 since the last X-ray outburst seen in 2010. These observations support the accretion disk scenario. Further, while IC 3599 remains in low emission states, the long-term X-ray light curve of IC 3599 reveals ongoing strong variability of a factor of a few. The most remarkable event is a mini flare of a factor of 10 in X-rays in December 2022. After that flare, the otherwise supersoft X-ray spectrum shows an exceptional hardening, reminiscent of a temporary corona formation.

[20]  arXiv:2404.19129 [pdf, other]

Title: A Panchromatic Study of the X-ray Binary Population in NGC 300 on Sub-Galactic Scales

Authors: Breanna A. Binder, Rosalie Williams, Jacob Payne, Michael Eracleous, Alexander Belles, Benjamin F. Williams

Comments: Accepted to AAS Journals; 22 pages, 12 figures, 6 tables

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)

The population-wide properties and demographics of extragalactic X-ray binaries (XRBs) correlate with the star formation rates (SFRs), stellar masses ($M_{\star}$), and environmental factors (such as metallicity, $Z$) of their host galaxy. Although there is evidence that XRB scaling relations ($L_X$/SFR for high mass XRBs [HMXBs] and $L_X$/$M_{\star}$ for low mass XRBs [LMXBs]) may depend on metallicity and stellar age across large samples of XRB-hosting galaxies, disentangling the effects of metallicity and stellar age from stochastic effects, particularly on subgalactic scales, remains a challenge. We use archival X-ray through IR observations of the nearby galaxy NGC 300 to self-consistently model the broadband spectral energy distribution and examine radial trends in its XRB population. We measure a current ($<$100 Myr) SFR of 0.18$\pm$0.08 $M_{\odot}$ yr$^{-1}$ and $M_{\star}$= $(2.15^{+0.26}_{-0.14})\times10^9$ $M_{\odot}$. Although we measure a metallicity gradient and radially resolved star formation histories that are consistent with the literature, there is a clear excess in the number of X-ray sources below $\sim10^{37}$ erg s$^{-1}$ that are likely a mix of variable XRBs and additional background AGN. When we compare the subgalactic $L_X$/SFR ratios as a function of $Z$ to the galaxy-integrated $L_X$-SFR-$Z$ relationships from the literature, we find that only the regions hosting the youngest ($\lesssim$30 Myr) HMXBs agree with predictions, hinting at time evolution of the $L_X$-SFR-$Z$ relationship.

[21]  arXiv:2404.19131 [pdf, other]

Title: Capillary processes in extraterrestrial contexts

Authors: Daniel Cordier, Gerard Liger-Belair, David A. Bonhommeau, Thomas Seon, Thomas Appere, Nathalie Carrasco

Comments: This paper is accepted in "Journal of Geophysical Research: Planet". Data and softwares are publicly available at this https URL

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Geophysics (physics.geo-ph)

The Earth is no longer the only known celestial body containing one or more liquid phases. The Cassini spacecraft has discovered seas of hydrocarbons at the surface of Titan, while a series of corroborating evidences argue in favour of the existence of an aqueous ocean beneath the icy crust of several moons. Capillarity embraces a family of physical processes occurring at the free surface of a liquid. These phenomena depend on the liquid properties and on the local planetary conditions. Capillarity may have important direct or indirect implications on the geoscientific and astrobiological points of view. In this paper, we discuss capillarity physics among solar system objects and expected consequences for planetary science.

[22]  arXiv:2404.19151 [pdf, other]

Title: Long term CCD photometry of the distant cluster NGC 2419: the CMD revisited

Authors: A. Arellano Ferro, S. Muneer, Sunetra Giridhar, I. Bustos Fierro, M. A. Yepez, G.A. García Pérez, G. Rios Segura

Comments: 19 pages, 11 figures, 3 tables

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

Employing \emph{VI} images of NGC 2419 acquired over 17 years, light curves for most of the known variables in the field of the cluster are produced. A cluster membership analysis for about 3100 stars in the cluster field with proper motions from $Gaia$-DR3, revealed the presence of member stars as far as 140 pc from the cluster center and enabled the construction of a cleaner CMD free of field stars. It was found that RRab and RRc stars share the inter-order region in the instability strip, which is unusual for OoII clusters. Theoretical considerations confirm that Pop II cepheids are descendants of extreme ZAHB blue tail stars with very thin envelopes of about 10\% of the total mass. Member RR Lyrae stars were employed to calculate independent estimates of the mean cluster metallicity and distance; we found [Fe/H]$_{\rm UV}= -1.90 \pm 0.27$ and $D=86.3 \pm 5.0$ kpc from the RRab and [Fe/H]$_{\rm UV}= -1.88 \pm 0.30$ and $D=83.1 \pm 8.1$ kpc from the RRc light curves.

[23]  arXiv:2404.19179 [pdf, other]

Title: On the Determining Physical Factor of Jet-Related Coronal Mass Ejection's Morphology in the High Corona

Authors: Yadan Duan, Yuandeng Shen, Zehao Tang, Chenrui Zhou, Song Tan

Comments: 15 pages, 15 figures, 2 tables, accepted by ApJ

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

A solar jet can often cause coronal mass ejections (CMEs) with different morphologies in the high corona, for example, jet-like CMEs, bubble-like CMEs, and so-called twin CMEs that include a pair of simultaneous jet-like and bubble-like CMEs. However, what determines the morphology of a jet-related CME is still an open question. Using high spatiotemporal resolution stereoscopic observations taken by the Solar Dynamics Observatory (SDO) and the Solar Terrestrial Relations Observatory (STEREO) from October 2010 to December 2012, we performed a statistical study of jet-related CMEs to study the potential physical factors that determine the morphology of CMEs in the outer corona. Our statistical sample includes 16 jet-related CME events of which 7 are twin CME events and 9 are jet-like narrow CMEs. We find that all CMEs in our sample were accompanied by filament-driven blowout jets and Type III radio bursts during their initial formation and involved magnetic reconnection between filament channels and the surrounding magnetic fields. Most of our cases occurred in a fan-spine magnetic configuration. Our study suggests that the bubble-like components of twin CMEs lacking an obvious core are related to the expansion of the closed-loop systems next to the fan-spine topology, while the jet-like component is from the coronal extension of the jet plasma along open fields. Based on the statistical results, we conclude that the morphology of jet-related CMEs in the high corona may be related to the filament length and the initial magnetic null point height of the fan-spine structures.

[24]  arXiv:2404.19181 [pdf, other]

Title: Low-energy Injection and Nonthermal Particle Acceleration in Relativistic Magnetic Turbulence

Authors: Divjyot Singh, Omar French, Fan Guo, Xiaocan Li

Comments: 11 pages, 7 figures, 1 animation, Submitted to ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)

Relativistic magnetic turbulence has been proposed as a process for producing nonthermal particles in high-energy astrophysics. The particle energization may be contributed by both magnetic reconnection and turbulent fluctuations, but their interplay is poorly understood. It has been suggested that during magnetic reconnection the parallel electric field dominates the particle acceleration up to the lower bound of the power-law particle spectrum, but recent studies show that electric fields perpendicular to the magnetic field can play an important, if not dominant role. In this study, we carry out fully kinetic particle-in-cell simulations of magnetically dominated decaying turbulence in a relativistic pair plasma. For a fixed magnetization parameter $\sigma_0 = 20$, we find that the injection energy~$\varepsilon_{\rm inj}$ converges with increasing domain size to~$\varepsilon_{\rm inj} \simeq 10 \, m_ec^2$. In contrast, the power-law index, the cut-off energy, and the power-law extent increase steadily with domain size. We trace a large number of particles and evaluate the contributions of the work done by the parallel ($W_\parallel$) and perpendicular ($W_\perp$) electric fields during both the injection phase and the post-injection phase. We find that during the injection phase, the $W_\perp$ contribution increases with domain size, suggesting that it may eventually dominate injection for a sufficiently large domain. In contrast, both components contribute equally during the post-injection phase, insensitive to the domain size. For high energy ($\varepsilon \gg \varepsilon_{\rm inj}$) particles, $W_\perp$ dominates the subsequent energization. These findings may improve our understanding of nonthermal particles and their emissions in astrophysical plasmas.

[25]  arXiv:2404.19194 [pdf, other]

Title: Updated observational constraints on spatially-flat and non-flat $Λ$CDM and XCDM cosmological models

Authors: Javier de Cruz Perez, Chan-Gyung Park, Bharat Ratra

Comments: 71 pages, 33 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

We study 6 LCDM models, with 4 allowing for non-flat geometry and 3 allowing for a non-unity lensing consistency parameter $A_L$. We also study 6 XCDM models with a dynamical dark energy density X-fluid with equation of state $w$. For the non-flat models we use two different primordial power spectra, Planck $P(q)$ and new $P(q)$. These models are tested against: Planck 2018 CMB power spectra (P18) and lensing potential power spectrum (lensing), and an updated compilation of BAO, SNIa, $H(z)$, and $f\sigma_8$ data [non-CMB data]. P18 data favor closed geometry for the LCDM and XCDM models and $w<-1$ (phantom-like dark energy) for the XCDM models while non-CMB data favor open geometry for the LCDM models and closed geometry and $w>-1$ (quintessence-like dark energy) for the XCDM models. When P18 and non-CMB data are jointly analyzed there is weak evidence for open geometry and moderate evidence for quintessence-like dark energy. Regardless of data used, $A_L>1$ is always favored. The XCDM model constraints obtained from CMB data and from non-CMB data are incompatible, ruling out the 3 $A_L = 1$ XCDM models at $> 3\sigma$. In the 9 models not ruled out, for the P18+lensing+non-CMB data set we find little deviation from flat geometry and moderate deviation from $w=-1$. In all 6 non-flat models (not ruled out), open geometry is mildly favored, and in all 3 XCDM+$A_L$ models (not ruled out) quintessence-like dark energy is moderately favored (by at most $1.6 \sigma$). In the $A_L = 1$ non-flat LCDM cases, we find for P18+lensing+non-CMB data $\Omega_k = 0.0009 \pm 0.0017$ [$0.0008 \pm 0.0017$] for the Planck [new] $P(q)$ model, favoring open geometry. The flat LCDM model remains the simplest (largely) observationally-consistent cosmological model. Our cosmological parameter constraints obtained for the flat LCDM model (and other models) are the most restrictive results to date (Abridged).

[26]  arXiv:2404.19208 [pdf, other]

Title: Optical Spectroscopy of Type Ia Supernovae by the Carnegie Supernova Projects I and II

Authors: N. Morrell (1), M. M. Phillips (1), G. Folatelli (2, 3), M. D. Stritzinger (4), M. Hamuy (5), N. B. Suntzeff (6), E. Y. Hsiao (7), F. Taddia (4), C. R. Burns (8), P. Hoeflich (7), C. Ashall (9), C. Contreras (1), L. Galbany (10, 11), J. Lu (7), A. L. Piro (8), J. Anais (1), E. Baron (12, 13, 14), A. Burrow (14), L. Busta (1), A. Campillay (1, 15), S. Castellón (1), C. Corco (1, 16), T. Diamond (7, 17), W. L. Freedman (18), C. González (1), K. Krisciunas (6), S. Kumar (7), S. E. Persson (8), J. Serón (19), M. Shahbandeh (7), S. Torres (16), S. A. Uddin (20), J. P. Anderson (21, 22), C. Baltay (23), C. Gall (4, 24), A. Goobar (25), E. Hadjiyska (23), S. Holmbo (4), M. Kasliwal (26), C. Lidman (27), G. H. Marion (28), P. Mazzali (29, 30), P. Nugent (31, 32), S. Perlmutter (32, 31), et al. (16 additional authors not shown)

Comments: 59 pages, 16 figures, accepted for publication in The Astrophysical Journal

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We present the second and final release of optical spectroscopy of Type Ia Supernovae (SNe Ia) obtained during the first and second phases of the Carnegie Supernova Project (CSP-I and CSP-II). The newly released data consist of 148 spectra of 30 SNe Ia observed in the course of the CSP-I, and 234 spectra of 127 SNe Ia obtained during the CSP-II. We also present 216 optical spectra of 46 historical SNe Ia, including 53 spectra of 30 SNe Ia observed by the Cal\'an/Tololo Supernova Survey. We combine these observations with previously published CSP data and publicly-available spectra to compile a large sample of measurements of spectroscopic parameters at maximum light, consisting of pseudo-equivalent widths and expansion velocities of selected features, for 232 CSP and historical SNe Ia (including more than 1000 spectra). Finally, we review some of the strongest correlations between spectroscopic and photometric properties of SNe Ia. Specifically, we define two samples: one consisting of SNe Ia discovered by targeted searches (most of them CSP-I objects) and the other composed of SNe Ia discovered by untargeted searches, which includes most of the CSP-II objects. The analysed correlations are similar for both samples. We find a larger incidence of SNe Ia belonging to the Cool (CL)and Broad Line (BL) Branch subtypes among the events discovered by targeted searches, Shallow Silicon (SS) SNe Ia are present with similar frequencies in both samples, while Core Normal (CN) SNe Ia are more frequent in untargeted searches.

[27]  arXiv:2404.19272 [pdf, other]

Title: Chandra Study of the Proper Motion of HST-1 in the Jet of M87

Authors: Rameshan Thimmappa, Joseph Neilsen, Daryl Haggard, Michael A. Nowak, Sera Markoff

Comments: Accepted for publication in ApJ. 9 pages, 13 figures, 1 table

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

The radio galaxy M87 is well known for its jet, which features a series of bright knots observable from radio to X-ray wavelengths. We analyze the X-ray image and flux variability of the knot HST-1 in the jet. Our analysis includes all 112 available \textit{Chandra} ACIS-S observations from 2000-2021, with a total exposure time of $\sim$887 ks. We use de-convolved images to study the brightness profile of the X-ray jet and measure the relative separation between the core and HST-1. From 2003-2005 (which coincides with a bright flare from HST-1), we find a correlation between the flux of HST-1 and its offset from the core. In subsequent data, we find a steady increase in this offset, which implies a bulk superluminal motion for HST-1 of 6.6$\pm$0.9 c (2.0$\pm$0.3 pc yr$^{-1}$), in keeping with prior results. We discuss models for the flux-offset correlation that feature either two or four emission regions separated by \textbf{tens} of parsecs. We attribute these results to moving shocks in the jet, that allow us to measure the internal structure of the jet.

[28]  arXiv:2404.19298 [pdf, other]

Title: Study of bound and resonant states of NS molecule in the R-matrix approach

Authors: F. Iacob, T. Meltzer, J. Zs. Mezei, I. F. Schneider, J. Tennyson

Comments: 7 pages, 11 figures

Journal-ref: J. Phys. B: At. Mol. Opt. Phys. 55 (2022) 235202 (9pp)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Atomic Physics (physics.atom-ph)

The bound and resonance states along with corresponding autoionization widths for nitrogen sulphide (NS) molecule are determined using electron NS$^+$ cation scattering calculations. The calculations are performed for $^2{\Sigma}^+$, $^2{\Pi}$ and $^2\Delta$ total symmetries using the ab initio R-matrix method for both bound and continuum states. Calculations are performed on a grid of 106 points for internuclear separations between 1.32 and 3 $\AA$. The resonance states yield dissociative potential curves which, when considered together with their widths, provide input for models of different electron-cation collision processes including dissociative recombination, and rotational and vibrational excitation. Curves and couplings which will lead directly to dissociative recombination are identified.

[29]  arXiv:2404.19300 [pdf, other]

Title: Phase-Dependent Spectral Shape Changes in the Ultraluminous X-Ray Pulsar NGC 5907 ULX1

Authors: Daiki Miura (1 and 2), Shogo B. Kobayashi (3), Hiroya Yamaguchi (2 and 1) ((1) Department of Physics, Graduate School of Science, The University of Tokyo, (2) Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), (3) Department of Physics, Tokyo University of Science)

Comments: 14 pages, 6 figures, accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Discovery of coherent pulsations from several ultraluminous X-ray pulsars (ULXPs) has provided direct evidence of super-critical accretion flow. However, geometrical structure of such accretion flow onto the central neutron star remains poorly understood. NGC 5907 ULX1 is one of the most luminous ULXPs with the luminosity exceeding $10^{41}~{\rm erg~s^{-1}}$. Here we present a broadband X-ray study of this ULXP using the data from simultaneous observations with XMM-Newton and NuSTAR conducted in July 2014. The phase-resolved spectra are well reproduced by a model consisting of a multicolor disk blackbody emission with a temperature gradient of $p = 0.5~(T \propto r^{-p})$ and a power law with an exponential cutoff. The disk component is phase-invariant, and has an innermost temperature of $\sim 0.3~{\rm keV}$. Its normalization suggests a relatively low inclination angle of the disk, in contrast to the previous claim in other literature. The power law component, attributed to the emission from the accretion flow inside the magnetosphere of the neutron star, indicates phase-dependent spectral shape changes; the spectrum is slightly harder in the pre-peak phase than in the post-peak phase. This implies that the magnetosphere has an asymmetric geometry around the magnetic axis, and that hotter regions close to the magnetic pole become visible before the pulse peak.

[30]  arXiv:2404.19302 [pdf, other]

Title: Dissociative recombination of the CH$^+$ molecular ion at low energy

Authors: K. Chakrabarti, J. Zs Mezei, O. Motapon, A. Faure, O. Dulieu, K. Hassouni, I. F. Schneider

Comments: 8 pages, 8 figures

Journal-ref: J. Phys. B: At. Mol. Opt. Phys. 51 (2018) 104002 (8pp)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Atomic Physics (physics.atom-ph); Plasma Physics (physics.plasm-ph)

The reactive collisions of the CH$^+$ molecular ion with electrons is studied in the framework of the multichannel quantum defect theory, taking into account the contribution of the core-excited Rydberg states. In addition to the $X^1\Sigma^+$ ground state of the ion, we also consider the contribution to the dynamics of the $a^3\Pi$ and $A^1\Pi$ excited states of CH$^+$. Our results - in the case of the dissociative recombination in good agreement with the storage ring measurements - rely on decisive improvements - complete account of the ionisation channels and accurate evaluation of the reaction matrix - of a previously used model.

[31]  arXiv:2404.19322 [pdf, other]

Title: Neutrinos in Cosmology

Authors: Eleonora Di Valentino, Stefano Gariazzo, Olga Mena

Comments: 11 pages, 1 figure. This is a pre-print of a chapter for the Encyclopedia of Astrophysics (edited by I. Mandel, section editor C. Howlett) to be published by Elsevier as a Reference Module

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)

Neutrinos are the least known particle in the Standard Model of elementary particle physics. They play a crucial role in cosmology, governing the universe's evolution and shaping the large-scale structures we observe today. In this chapter, we review crucial topics in neutrino cosmology, such as the neutrino decoupling process in the very early universe. We shall also revisit the current constraints on the number of effective relativistic degrees of freedom and the departures from its standard expectation of 3. Neutrino masses represent the very first departure from the Standard Model of elementary particle physics and may imply the existence of new unexplored mass generation mechanisms. Cosmology provides the tightest bound on the sum of neutrino masses, and we shall carefully present the nature of these constraints, both on the total mass of the neutrinos and on their precise spectrum. The ordering of the neutrino masses plays a major role in the design of future neutrino mass searches from laboratory experiments, such as neutrinoless double beta decay probes. Finally, we shall also present the futuristic perspectives for an eventual direct detection of cosmic, relic neutrinos.

[32]  arXiv:2404.19323 [pdf, other]

Title: Energy dependence of Quasi-periodic oscillations in accreting X-ray pulsars

Authors: Hemanth Manikantan, Biswajit Paul, Rahul Sharma, Pragati Pradhan, Vikram Rana

Comments: 22 pages, Accepted for publication in Monthly Notices of the Royal Astronomical Society

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We present the results from an investigation of the energy dependence of Quasi-Periodic Oscillations (QPOs) exhibited by accreting X-ray pulsars using data from archival \textit{XMM-Newton}, \textit{NuSTAR}, \textit{RXTE}, and \textit{NICER} observations. In a search for the presence of QPOs in 99 \textit{XMM-Newton} and \textit{NuSTAR} observations, we detected QPOs in eleven observations of five sources, viz., 4U 1626--67 (48 mHz), IGR J19294+1816 (30 mHz), V 0332+53 (2, 18 and 40 mHz), Cen X--3 (30 mHz), and XTE J1858+034 (180 mHz). A positive correlation of the QPO rms amplitude with energy is exhibited by 4U 1626--67, IGR J19294+1816, Cen X--3 and XTE J1858+034, while no energy dependence is observed in V 0332+53. We also analysed the energy spectrum to decouple thermal (soft-excess) from non-thermal emission and determine if the soft-excess has different QPO properties. We found no evidence for different QPO characteristics of the soft excess. The \textit{NuSTAR} observations of V 0332+53 during the Type-I outburst in 2016 show the presence of twin QPOs at 2.5 mHz and 18 mHz, while the \textit{XMM-Newton} and \textit{NuSTAR} observations during the Type-II outburst in 2015 show a QPO at 40 mHz. We review the observed QPO properties in the context of QPOs found in other types of accreting sources and the models usually used to explain the QPOs in accreting X-ray pulsars.

[33]  arXiv:2404.19340 [pdf, other]

Title: Revisiting the Constraint on Equation of State of Neutron Star based on the Binary Neutron Star Mergers

Authors: Yun-Peng Li, Zhi-Lin Chen, Da-Bin Lin, En-Wei Liang

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

The merger of neutron star (NS)-NS binary can form different production of the compact remnant, among which the supramassive NS (SMNS) could create an internal plateau and the followed steep decay marks the collapse of the SMNS. The proportion of SMNS and the corresponding collapse-time are often used to constrain the NS equation of state (EoS). This paper revisits this topic by considering the effect of an accretion disk on the compact remnant, which is not considered in previous works. Compared with previous works, the collapse-time distribution (peaks $\sim$100 s) of the SMNSs formed from NS-NS merger is almost unaffected by the initial surface magnetic ($B_{{\rm s},i}$) of NS, but the total energy output of the magnetic dipole radiation from the SMNSs depends on $B_{{\rm s},i}$ significantly. Coupling the constraints from the SMNS fraction, we exclude some EoSs and obtain three candidate EoSs, i.e., DD2, ENG, and MPA1. By comparing the distributions of the collapse-time and the luminosity of the internal plateau (in the short gamma-ray bursts) for those from observations with those obtained based on the three candidate EoSs, it is shown that only the EoS of ENG is favored. Our sample based on the ENG EOS and a mass distribution motivated by Galactic systems suggests that approximately $99\%$ of NS-NS mergers collapse to form a black hole within $10^7$s. This includes scenarios forming a BH promptly ($36.5\%$), a SMNS ($60.7\%$), or a stable NS that transitions into a BH or a SMNS following accretion ($2.1\%$). It also indicates that the remnants for GW170817 and GW190425, and the second object of GW190814 are more likely to be BHs.

[34]  arXiv:2404.19380 [pdf, other]

Title: Strength in numbers: A multiphase wind model with multiple cloud populations

Authors: C. Nikolis, M. Gronke

Comments: 17 pages, 15 figures, to be published in Monthly Notices of the Royal Astronomical Society

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Galactic outflows have a multiphase nature making them challenging to model analytically. Many previous studies have tried to produce models that come closer to reality. In this work, we continue these efforts and describe the interaction of the hot wind fluid with multiple cold cloud populations, with their number density determined by different probability density functions. To do so, we introduced realistic cloud-wind interaction source terms and a time-varying cooling area. We find that the model reproduces well results from small-scale hydrodynamic simulations, but exhibits a general destructive behavior both for a single cloud population as well as multiple ones. We show that including multiple cloud populations can alter the evolution of the wind drastically. We also compare our model to observations and show that the differential acceleration of multiple clouds can lead to a non-negligible velocity `dispersion' relevant for down-the-barrel studies. Furthermore, we compute the emitted cooling surface brightness and find it generally too faint to explain observed Lyman-$\alpha$ halos.

[35]  arXiv:2404.19388 [pdf, other]

Title: Comparative Mid-Infrared Spectroscopy of Dark, Primitive Asteroids: Does Shared Taxonomic Class Indicate Shared Silicate Composition?

Authors: Oriel A. Humes, Audrey C. Martin, Cristina A. Thomas, Joshua P. Emery

Comments: 22 Pages, 9 figures, draft version accepted for publication in PSJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Primitive asteroids with low albedos and red slopes in the visible and near infrared (VNIR) are found in both the Main Belt and the Jupiter Trojan clouds. In order to determine whether the VNIR spectral similarities of primitive Main Belt asteroids and Jupiter Trojans are reflective of a true compositional similarity, we compare the mid-infrared silicate emission features of Main Belt and Jupiter Trojan asteroids. Using archival data from the Spitzer Space Telescope's IRS spectrograph and observations from the Stratospheric Observatory for Infrared Astronomy's (SOFIA) FORCAST instrument, we analyze the 5-40 micron spectra of thirteen primitive Main Belt asteroids and compare them to those of Jupiter Trojans in the literature. We find that while many primitive asteroids in the Main Belt resemble their Trojan counterparts with strong spectral signatures of olivine-rich high-porosity silicate regoliths, we identify (368) Haidea as a spectrally distinctive asteroid that lacks strong evidence of olivine in its MIR spectrum. Differences in silicate compositions among D-type asteroids imply a diversity of origins for primitive asteroids.

[36]  arXiv:2404.19390 [pdf, other]

Title: EL meteorites do date the giant planet instability

Authors: Chrysa Avdellidou, Marco Delbo, David Nesvorny, Kevin J. Walsh, Alessandro Morbidelli

Comments: 4 pages, 1 figure; comment on arXiv:2404.10828

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

In our recent work, we combined dynamical simulations, meteoritic data and thermal models as well as asteroid observations to argue that the current parent body of the EL meteorites was implanted into the asteroid belt not earlier than 60 Myr after the beginning of the Solar System and that the most likely capture mechanism was the giant planet orbital instability. In the study "The link between Athor and EL meteorites does not constrain the timing of the giant planet instability" that appeared in arXiv, Izidoro and collaborators argue that the implantation of Athor into the asteroid belt does not necessarily require that the giant planet orbital instability occurred at the implantation time. Here we provide further arguments that, in the end, the giant planet instability is still the most likely dynamical process to implant asteroid Athor into the asteroid main belt between 60 and 100 Myr after the beginning of the Solar System.

[37]  arXiv:2404.19437 [pdf, other]

Title: Quintom cosmology and modified gravity after DESI 2024

Authors: Yuhang Yang, Xin Ren, Qingqing Wang, Zhiyu Lu, Dongdong Zhang, Yi-Fu Cai, Emmanuel N. Saridakis

Comments: 10 pages, 3 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

We reconstruct the cosmological background evolution under the scenario of dynamical dark energy through the Gaussian process approach, using the latest Dark Energy Spectroscopic Instrument (DESI) baryon acoustic oscillations (BAO) \cite{DESI:2024mwx} combined with other observations. Our results reveal that the reconstructed dark-energy equation-of-state (EoS) parameter $w(z)$ exhibits the so-called quintom-B behavior, crossing $-1$ from phantom to quintessence regime as the universe expands. We investigate under what situation this type of evolution could be achieved from the perspectives of field theories and modified gravity. In particular, we reconstruct the corresponding actions for $f(R)$, $f(T)$, and $f(Q)$ gravity, respectively. We explicitly show that, certain modified gravity can exhibit the quintom dynamics and fit the recent DESI data efficiently, and for all cases the quadratic deviation from the $\Lambda$CDM scenario is mildly favored.

[38]  arXiv:2404.19443 [pdf, ps, other]

Title: Rediscussion of eclipsing binaries. Paper XIX. The long-period solar-type system V454 Aurigae

Authors: John Southworth

Comments: Accepted for publication in The Observatory on 2nd April 2024. 14 pages, 4 tables, 3 black/white figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

V454 Aur is an eclipsing binary system containing two solar-type stars on an orbit of relatively long period (P = 27.02 d) and large eccentricity (e = 0.381). Eclipses were detected using data from the Hipparcos satellite, and a high-quality double-lined spectroscopic orbit has been presented by Griffin (2001). The NASA Transiting Exoplanet Survey Satellite (TESS) has observed the system during eight sectors, capturing ten eclipses in their entirety. V454 Aur is unusual in that the primary star - the star eclipsed at the deeper minimum - is less massive, smaller \emph{and} cooler than its companion. This phenomenon can occur in certain configurations of eccentric orbits when the stars are closer together at the primary eclipse, causing a larger area to be eclipsed than at the secondary. We use the radial velocity measurements from Griffin and the light curves from TESS to determine the masses and radii of the component stars for the first time, finding masses of 1.034 +/- 0.006 Msun and 1.161 +/- 0.008 Msun, and radii of 0.979 +/- 0.003 Rsun and 1.211 +/- 0.003 Rsun. Our measurement of the distance to the system is consistent with that from the Gaia DR3 parallax. A detailed spectroscopic study to determine chemical abundances and more precise temperatures is encouraged. Finally, we present equations to derive the effective temperatures of the stars from the inferred temperature of the system as a whole, plus the ratio of the radii and either the surface brightness or light ratio of the stars.

[39]  arXiv:2404.19471 [pdf, other]

Title: AGN constraints on neutrino-dark matter scattering

Authors: James M. Cline

Comments: 4.1 pages, 4 figures. Talk given at Moriond VHEPU based on arXiv:2209.02713 and arXiv:2301.08756

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)

The IceCube collaboration has identified neutrinos of energy $\sim 10-100$ TeV from the blazar TXS 0506+056 and the active galaxy NGC 1068, which must have traveled through a dense dark matter spike surrounding the supermassive black holes that power the galactic nuclei. We use this to set new constraints on dark matter-neutrino scattering, and interpret the results in terms of a dark photon that couples to baryon minus lepton number.

[40]  arXiv:2404.19473 [pdf, other]

Title: The recent star formation histories of nearby galaxies on resolved scales

Authors: Maria Lomaeva, Amélie Saintonge, Ilse De Looze

Comments: 15 pages, 9 figures. Accepted for publication in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Star formation histories (SFHs) of galaxies are affected by a variety of factors, both external (field vs. cluster/group) and internal (presence of a bar and AGN, morphological type). In this work, we extend our previous study and apply the <SFR5>/<SFR200> metric to a sample of eleven nearby galaxies with MUSE observations. Based on a combination of H$\alpha$ and UV photometry, <SFR5>/<SFR200> is sensitive to star formation timescales of ~5-200 Myr and therefore measures the present-day rate of change in the star formation rate, dSFR/dt. Within this limited galaxy sample, we do not observe systematic variations between the global value of <SFR5>/<SFR200> and the presence of an active galactic nucleus, stellar bar, nor with group or cluster membership. Within some of the individual galaxies, we however observe significant differences in <SFR5>/<SFR200> between the arm and interarm regions. In half of the galaxies, the recent SFH of both arm and interarm regions has been very similar. However, in the galaxies with higher bulge-to-total light ratios and earlier morphological type, the SFR is declining more rapidly in the interarm regions. This decline in SFR is not a result of low molecular gas surface density or a decrease in the star formation efficiency, implying that other factors are responsible for this SFR decrease.

[41]  arXiv:2404.19504 [pdf, other]

Title: SPHERE RefPlanets: Search for epsilon Eridani b and warm dust

Authors: C. Tschudi, H.M. Schmid, M. Nowak, H. Le Coroller, S. Hunziker, R.G. van Holstein, C. Perrot, D. Mouillet, J.-C. Augereau, A. Bazzon, J.L. Beuzit, A. Boccaletti, M.J. Bonse, G. Chauvin, S. Desidera, K. Dohlen, C. Dominik, N. Engler, M. Feldt, J.H. Girard, R. Gratton, Th. Henning, M. Kasper, P. Kervella, A.-M. Lagrange, M. Langlois, P. Martinez, F.Ménard, M.R. Meyer, J. Milli, J. Pragt, P. Puget, S.P. Quanz, R. Roelfsema, J.-F. Sauvage, J. Szulagyi, Ch. Thalmann, A. Zurlo

Comments: 26 pages, 20 figures, 5 tables. Accepted for publication in A&A

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)

We carried out very deep VLT/SPHERE imaging polarimetry of the nearby system Eps Eri based on 38.5 hours of integration time with a 600 - 900 nm broadband filter to search for polarized scattered light from a planet or from circumstellar dust using AO, coronagraphy, high precision differential polarimetry, and angular differential imaging. We have improved several data reduction and post-processing techniques and also developed new ones to further increase the sensitivity of SPHERE/ZIMPOL. The data provide unprecedented contrast limits, but no significant detection of a point source or an extended signal from circumstellar dust. For each observing epoch, we obtained a point source contrast for the polarized intensity between $2\cdot 10^{-8}$ and $4\cdot 10^{-8}$ at the expected separation of the planet Eps Eri b of 1'' near quadrature phase. The polarimetric contrast limits are about six to 50 times better than the intensity limits because polarimetric imaging is much more efficient in speckle suppression. Combining the entire 14-month data set to the search for a planet moving on a Keplerian orbit with the K-Stacker software further improves the contrast limits by a factor of about two, to about $8 \cdot 10^{-9}$ at 1''. This would allow the detection of a planet with a radius of about 2.5 Jupiter radii. The surface brightness contrast limits achieved for the polarized intensity from an extended scattering region are about 15 mag arcsec$^{-2}$ at 1'', or up to 3 mag arcsec$^{-2}$ deeper than previous limits. For Eps Eri, these limits exclude the presence of a narrow dust ring and they constrain the dust properties. This study shows that the polarimetric contrast limits for reflecting planets with SPHERE/ZIMPOL can be improved to a level $<10^{-8}$ simply by collecting more data over many nights and using the K-Stacker software.

[42]  arXiv:2404.19524 [pdf, other]

Title: DARWIN/XLZD: a future xenon observatory for dark matter and other rare interactions

Authors: Laura Baudis

Comments: 7 pages, 10 figures. Accepted to appear in Nuc. Phys. B special issue "Nobel Symposium on Dark Matter" (NS 182)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)

The DARWIN/XLZD experiment is a next-generation dark matter detector with a multi-ten-ton liquid xenon time projection chamber at its core. Its principal goal will be to explore the experimentally accessible parameter space for Weakly Interacting Massive Particles (WIMPs) in a wide mass-range, until interactions of astrophysical neutrinos will become an irreducible background. The prompt scintillation light and the charge signals induced by particle interactions in the liquid xenon target will be observed by VUV-sensitive, ultra-low background photosensors. Besides its excellent sensitivity to WIMPs with masses above $\sim$5\,GeV, such a detector with its large mass, low-energy threshold and ultra-low background level will also be sensitive to other rare interactions, and in particular also to bosonic dark matter candidates with masses at the keV-scale. We present the detector concept, discuss the main sources of backgrounds, the technological challenges and some of the ongoing detector design and R&D efforts, as well as the large-scale demonstrators. We end by discussing the sensitivity to particle dark matter interactions.

[43]  arXiv:2404.19529 [pdf, other]

Title: Status Report on Global Pulsar-Timing-Array Efforts to Detect Gravitational Waves

Authors: Joris P.W. Verbiest, Sarah J. Vigeland, Nataliya K. Porayko, Siyuan Chen, Daniel J. Reardon

Comments: 37 pages, 4 figures, 4 tables. Accepted for publication in "Results in Physics" special issue

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

The stability of the spin of pulsars and the precision with which these spins can be determined, allows many unique tests of interest to physics and astrophysics. Perhaps the most challenging and revolutionary of these, is the detection of nanohertz gravitational waves. An increasing number of efforts to detect and study long-period gravitational waves by timing an array of pulsars have been ongoing for several decades and the field is moving ever closer to actual gravitational-wave science. In this review article, we summarise the state of this field by presenting the current sensitivity to gravitational waves and by reviewing recent progress along the multiple lines of research that are part of the continuous push towards greater sensitivity. We also briefly review some of the most recent efforts at astrophysical interpretation of the most recent GW estimates derived from pulsar timing.

[44]  arXiv:2404.19530 [pdf, other]

Title: Prospects for weighing neutrinos in interacting dark energy models using joint observations of gravitational waves and $γ$-ray bursts

Authors: Lu Feng, Tao Han, Jing-Fei Zhang, Xin Zhang

Comments: 8 pages, 2 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

In this work, we explore the capability of future gravitational wave (GW) standard siren observations to constrain the total neutrino mass in some typical interacting dark energy (IDE) models. We examine the combined potential of the third-generation ground-based GW detector network and a short $\gamma$-ray burst (GRB) detector similar to the THESEUS telescope for cosmological analysis. Our findings suggest that future GW standard siren observations could modestly refine the upper limit on the total neutrino mass, enhancing it by $5\%$ to $10\%$ over the existing limit given by the CMB+BAO+SN data. Additionally, the future observations are expected to significantly improve the constraints on $\Omega_{\rm m}$ and $H_0$. Moreover, the measurements could enhance the precision of the coupling strength $\beta$ by $23\%$ to $42\%$.

[45]  arXiv:2404.19533 [pdf, other]

Title: Shocks in the Warm Neutral Medium I -- Theoretical model

Authors: Benjamin Godard (LPENS), Guillaume Pineau Des Forêts (IAS), Shmuel Bialy

Comments: Astronomy and Astrophysics - A\&A, In press

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Context. Atomic and molecular line emissions from shocks may provide valuable information on the injection of mechanical energy in the interstellar medium (ISM), the generation of turbulence, and the processes of phase transition between the Warm Neutral Medium (WNM) and the Cold Neutral Medium (CNM).Aims. In this series of papers, we investigate the properties of shocks propagating in the WNM. Our objective is to identify the tracers of these shocks, use them to interpret ancillary observations of the local diffuse matter, and provide predictions for future observations.
Methods. Shocks propagating in the WNM are studied using the Paris-Durham shock code, a multi-fluid model built to follow the thermodynamical and chemical structures of shock waves, at steady-state, in a plane-parallel geometry. The code, already designed to take into account the impact of an external radiation field, is updated to treat self-irradiated shocks at intermediate ($30<V_S <100$ km s$^{-1}$) and high velocity ($V_S \ge 100$ km s$^{-1}$) which emit ultraviolet (UV), extreme-ultraviolet (EUV), and X-ray photons. The couplings between the photons generated by the shock, the radiative precursor, and the shock structure are computed self-consistently using an exact radiative transfer algorithm for line emission. The resulting code is explored over a wide range of parameters ($0.1 \le n_H \le 2$ cm$^{-3}$, $10 \le V_S \le 500$ km s$^{-1}$, and $0.1 \le B \le 10$ $\mu$G) that covers the typical conditions of the WNM in the solar neighborhood.
Results. The explored physical conditions are prompt to the existence of a diversity of stationary magnetohydrodynamic solutions, including J-type, CJ-type, and C-type shocks. These shocks are found to naturally induce phase transition between the WNM and the CNM, provided that the postshock thermal pressure is larger than the maximum pressure of the WNM and that the maximum density allowed by magnetic compression is larger than the minimum density of the CNM. The input flux of mechanical energy is primarily reprocessed into line emissions from the X-ray to the submillimeter domain. Intermediate and high velocity shocks are found to generate a UV radiation field that scales as $V_S^3$ for $V_S < 100$ km s$^{-1}$ and as $V_S^2$ at higher velocities, and an X-ray radiation field that scales as $V_S^3$ for $V_S \ge 100$ km s$^{-1}$. Both radiation fields may extend over large distances in the preshock depending of the density of the surrounding medium and the hardness of the X-ray field which is solely driven by the shock velocity.
Conclusions. This first paper presents the thermochemical trajectories of shocks in the WNM and their associated spectra. It corresponds to a new milestone in the development of the Paris-Durham shock code and a stepping stone for the analysis of observations that will be carried out in forthcoming works.

[46]  arXiv:2404.19544 [pdf, other]

Title: Extinction and AGN over host galaxy contrast effects on the optical spectroscopic classification of AGN

Authors: L. Barquín-González, S. Mateos, F. J. Carrera, I. Ordovás-Pascual, A. Alonso-Herrero, A. Caccianiga, N. Cardiel, A. Corral, R.M. Domínguez, I. García-Bernete, G. Mountrichas, P. Severgnini

Comments: Accepted to Astronomy & Astrophysics. 15 pages, 21 figures

Subjects: Astrophysics of Galaxies (astro-ph.GA)

The optical spectroscopic classification of active galactic nuclei (AGN) into type 1 and type 2 can be understood in the frame of the AGN unification models. However, it remains unclear which physical properties are driving the classification into intermediate sub-types (1.0,1.2,1.5,1.8,1.9). To shed light on this issue, we present an analysis of the effect of extinction and AGN and host galaxy luminosities on sub-type determination for a sample of 159 X-ray selected AGN with a complete and robust optical spectroscopic classification. The sample spans a rest-frame 2 - 10 keV X-ray luminosity range of $10^{42}-10^{46}$ erg s$^{-1}$ and redshifts between 0.05 and 0.75. From the fitting of their UV-to-mid-infrared spectral energy distributions, we extracted the observed AGN over total AGN+galaxy contrast, optical/UV line-of-sight extinction as well as host galaxy and AGN luminosities. The observed contrast exhibits a clear decline with sub-type, distinguishing two main groups: 1.0-5 and 1.8-9/2. This difference is partly driven by an increase in extinction following the same trend. Nevertheless, 50% of 1.9s and 2s lack sufficient extinction to explain the lack of detection of broad emission lines, unveiling the necessity of an additional effect. Our findings show that 1.8-9/2s preferentially live in host galaxies with higher luminosities while displaying similar intrinsic AGN luminosities to 1.0-5s. Consequently, the AGN to host galaxy luminosity ratio diminishes, hindering the detection of the emission of the broad emission lines, resulting in the 1.8-9/2 classification of those with insufficient extinction. Thus, the combination of increasing extinction and decreasing AGN/galaxy luminosity ratio, mainly driven by an increasing host galaxy luminosity, constitutes the main reasons behind the sub-type classification into 1.0-5 and 1.8-9/2.

[47]  arXiv:2404.19549 [pdf, other]

Title: Cool-core, X-ray cavities and cold front revealed in RXCJ0352.9+1941 cluster by Chandra and GMRT observations

Authors: Satish S. Sonkamble, S. K. Kadam, Surajit Paul, M. B. Pandge, P. K. Pawar, M. K. Patil

Comments: 18 pages, 10 figures, Accepted for Journal of Astrophysics and Astronomy

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)

This paper presents a comprehensive analysis of 30 ks Chandra and 46.8 ks (13 Hr) 1.4 GHz GMRT radio data on the cool-core cluster RXCJ0352.9+1941 with an objective to investigate AGN activities at its core. This study confirms a pair of X-ray cavities at projected distances of about 10.30 kpc and 20.80 kpc, respectively, on the NW and SE of the X-ray peak. GMRT L band (1.4 GHz) data revealed a bright radio source associated with the core of this cluster hosting multiple jet-like emissions. The spatial association of the X-ray cavities with the inner pair of radio jets confirm their origin due to AGN outbursts. The 1.4 GHz radio power ${\rm 7.4 \pm 0.8 \times 10^{39} \, erg\, s^{-1}}$ is correlated with the mechanical power stored in the X-ray cavities ($\sim7.90\times 10^{44}$ erg s$^{-1}$), implying that the power injected by radio jets in the ICM is sufficient enough to offset the radiative losses. The X-shaped morphology of diffuse radio emission seems to be comprised of two pairs of orthogonal radio jets, likely formed due to a spin-flip of jets due to the merger of two systems. The X-ray surface brightness analysis of the ICM in its environment revealed two non-uniform, extended spiral-like emission structures on either side of the core, pointing towards the sloshing of gas due to a minor merger and might have resulted in a cold front at $\sim$31 arcsec (62 kpc) with a temperature jump of 1.44 keV.

[48]  arXiv:2404.19589 [pdf, other]

Title: Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade

Authors: R. Abbasi, M. Ackermann, J. Adams, S. K. Agarwalla, J. A. Aguilar, M. Ahlers, J.M. Alameddine, N. M. Amin, K. Andeen, C. Argüelles, Y. Ashida, S. Athanasiadou, L. Ausborm, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, S. Bash, V. Basu, R. Bay, J. J. Beatty, J. Becker Tjus, J. Beise, C. Bellenghi, C. Benning, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, E. Blaufuss, L. Bloom, S. Blot, F. Bontempo, J. Y. Book Motzkin, C. Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, J. Braun, B. Brinson, J. Brostean-Kaiser, L. Brusa, R. T. Burley, D. Butterfield, M. A. Campana, I. Caracas, K. Carloni, J. Carpio, S. Chattopadhyay, N. Chau, Z. Chen, D. Chirkin, S. Choi, B. A. Clark, A. Coleman, G. H. Collin, A. Connolly, J. M. Conrad, P. Coppin, R. Corley, P. Correa, et al. (360 additional authors not shown)

Comments: 24 pages, 19 figures, 2 tables, submitted to JINST

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex); Instrumentation and Detectors (physics.ins-det)

More than 10,000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests.

[49]  arXiv:2404.19601 [pdf, other]

Title: Recovery of the X-ray polarization of Swift J1727.8$-$1613 after the soft to hard spectral transition

Authors: J. Podgorný, J. Svoboda, M. Dovčiak, A. Veledina, J. Poutanen, P. Kaaret, S. Bianchi, A. Ingram, F. Capitanio, S. R. Datta, E. Egron, H. Krawczynski, G. Matt, F. Muleri, P.-O. Petrucci, T. D. Russell, J. F. Steiner, N. Bollemeijer, M. Brigitte, R. Emami, J. A. García, K. Hu, M. N. Iacolina, V. Kravtsov, L. Marra, G. Mastroserio, T. Muñoz-Darias, E. Nathan, M. Negro, A. Ratheesh, N. Rodriguez Cavero, R. Taverna, F. Tombesi, Y. J. Yang, W. Zhang, Y. Zhang

Comments: 7 pages, 6 figures. Submitted to A&A Letters

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We report on the detection of X-ray polarization in the black-hole X-ray binary Swift J1727.8$-$1613 during its dim hard spectral state by the Imaging X-ray Polarimetry Explorer (IXPE). This is the first detection of the X-ray polarization at the transition from the soft to the hard state in an X-ray binary. We find a 2$-$8 keV averaged polarization degree of (3.3 ${\pm}$ 0.4) % and the corresponding polarization angle of 3{\deg} ${\pm}$ 4{\deg}, which matches with the polarization detected during the rising stage of the outburst, in September$-$October 2023, within 1${\sigma}$ uncertainty. The observational campaign complements previous studies of this source and enables comparison of the X-ray polarization properties of a single transient across the X-ray hardness-intensity diagram. The complete recovery of X-ray polarization properties, including energy dependence, follows a dramatic drop of the X-ray polarization during the soft state. The new IXPE observations in the dim hard state at the reverse transition indicate that the accretion properties, including the geometry of the corona, appear to be strikingly similar to the bright hard state during the outburst rise even though the X-ray luminosities differ by two orders of magnitude.

[50]  arXiv:2404.19617 [pdf, other]

Title: More luminous red novae that require jets

Authors: Noam Soker (Technion, Israel)

Comments: Will be submitted in two days to allow for comments (including missing references)

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

I study two intermediate luminosity optical transients (ILOTs) classified as luminous red novae (LRNe) and argue that their modeling with a common envelope evolution (CEE) without jets encounters challenges. LRNe are ILOTs powered by violent binary interaction. Although popular in the literature is to assume a CEE is the cause of LRNe, I here repeat an old claim that many LRNe are powered by grazing envelope evolution (GEE) events; the GEE might end in a CEE or a detached binary system. I find that the LRN AT 2021biy might have continued to experience mass ejection episodes after its eruption and, therefore, might not suffered a full CEE during the outburst. This adds to an earlier finding that a jet-less model does not account for some of its properties. I find that a suggested jet-less CEE model for the LRN AT 2019zhd does not reproduce its photosphere radius evolution. These results that challenge jet-less models of two LRNe strengthen a previous claim that jets play major roles in powering ILOTs and shaping their ejecta and that in many LRNe, the more compact companion launches the jets during a GEE.

[51]  arXiv:2404.19628 [pdf, ps, other]

Title: A Wide Metallicity Range for Gyr-old Stars in the Nuclear Star Cluster

Authors: Brian Thorsbro, Rebecca Forsberg, Georges Kordopatis, Alessandra Mastrobuono-Battisti, Ross P. Church, R. Michael Rich, Nils Ryde, Mathias Schultheis, Shogo Nishiyama

Comments: 6 pages, 4 figures

Journal-ref: ApJL 958 L18 (2023)

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We report metallicities for three $\sim$Gyr-old stars in the Milky Way nuclear star cluster (NSC) using high-resolution near-infrared spectroscopy. We derive effective temperatures from a calibration with Sc line strength, which yields results in good agreement with other methods, and metallicities from spectral fits to Fe I lines. Our derived metallicities range from -1.2 < [Fe/H] < +0.5, a span of 1.7 dex. In addition we use isochrone projection to obtain masses of 1.6 to 4.3 M$_\odot$, and ages assuming single-star evolution. The oldest of these stars is 1.5 Gyr while the youngest and most metal-rich is only 100 Myr. The wide range in metallicity poses interesting questions concerning the chemical evolution and enrichment of the NSC and adds to the evidence for the presence of a young, metal-rich population in the NSC. We suggest that the candidate intermediate-age, metal-poor ([Fe/H] = -1.2) star may be best explained as a blue straggler from an underlying old population.

[52]  arXiv:2404.19655 [pdf, other]

Title: The Local Dark Matter Kinematic Substructure Based on LAMOST K Giants

Authors: Hai Zhu, Rui Guo, Juntai Shen, Jianglai Liu, Chao Liu, Xiang-Xiang Xue, Lan Zhang, Shude Mao

Subjects: Astrophysics of Galaxies (astro-ph.GA)

Numerical simulations indicate that correlations exist between the velocity distributions of stars and dark matter (DM). We study the local DM velocity distribution based on these correlations. We select K giants from LAMOST DR8 cross-matched with Gaia DR3, which has robust measurements of three-dimensional velocity and metallicity, and separate them into the disk, halo substructure and main halo components in the chemo-dynamical space utilizing the Gaussian Mixture Model. The substructure component is highly radially anisotropic, and possibly related to the Gaia-Enceladus-Sausage (GES) merger event, while the halo component is isotropic and accreted from the earliest mergers following the Maxwell-Boltzmann Distribution (Standard Halo Model, SHM). We find that the GES-like substructure contributes $\sim85\%$ of the local non-disk stars in the Solar neighbourhood, which is nearly invariant when applying different volume cuts or additional angular momentum constraints. Utilizing the metallicity-stellar-mass relation and the stellar-mass-halo-mass relation, we find that $\sim25_{-15}^{+24}\%$ of local DM is in the kinematic substructure. Combined with the stellar distributions of non-disk components, we compute the velocity distribution of local DM. The modified heliocentric velocity distribution of local DM shifts to a lower speed and has a sharper peak compared to the SHM, which yields updated detection limits for the DM direct detection experiments. Our work confirms that the local DM velocity distribution deviates from the SHM, and needs to be properly accounted in the DM detection experiments.

[53]  arXiv:2404.19676 [pdf, other]

Title: The Nature of X-Rays from Young Stellar Objects in the Orion Nebula Cluster -- A Chandra HETGS Legacy Project

Authors: Norbert S. Schulz, David P. Huenemoerder, David A. Principe, Marc Gagne, Hans Moritz Günther, Joel Kastner, Joy Nichols, Andrew Pollock, Thomas Preibisch, Paola Testa, Fabio Reale, Fabio Favata, Claude R. Canizares

Comments: Accepted by ApJ

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

The Orion Nebula Cluster (ONC) is the closest site of very young ($\sim$ 1 Myrs) massive star formation. The ONC hosts more than 1600 young and X-ray bright stars with masses ranging from $\sim$ 0.1 to 35 $M_\odot$. The Chandra HETGS Orion Legacy Project observed the ONC with the Chandra high energy transmission grating spectrometer (HETGS) for $2.1\,$Ms. We describe the spectral extraction and cleaning processes necessary to separate overlapping spectra. We obtained 36 high resolution spectra which includes a high brilliance X-ray spectrum of $\theta^1$ Ori C with over 100 highly significant X-ray lines. The lines show Doppler broadening between 300 and $400\;\mathrm{km}\;\mathrm{s}^{-1}$. Higher spectral diffraction orders allow us to resolve line components of high Z He-like triplets in $\theta^1$ Ori C with unprecedented spectral resolution. Long term light curves spanning $\sim$20 years show all stars to be highly variable, including the massive stars. Spectral fitting with thermal coronal emission line models reveals that most sources show column densities of up to a few times $10^{22}\,$cm$^{-2}$ and high coronal temperatures of 10 to 90 MK. We observe a bifurcation of the high temperature component where some stars show a high component of 40 MK, while others show above 60 MK indicating heavy flaring activity. Some lines are resolved with Doppler broadening above our threshold of $\sim200\;\mathrm{km}\;\mathrm{s}^{-1}$, up to $500\;\mathrm{km}\;\mathrm{s}^{-1}$. This data set represents the largest collection of HETGS high resolution X-ray spectra from young pre-MS stars in a single star-forming region to date.

[54]  arXiv:2404.19690 [pdf, other]

Title: FAUST XV. A disk wind mapped by CH$_3$OH and SiO in the inner 300 au of the NGC 1333 IRAS 4A2 protostar

Authors: M. De Simone, L. Podio, L. Chahine, C. Codella, C. J. Chandler, C. Ceccarelli, A. Lopez-Sepulcre, L. Loinard, B. Svoboda, N. Sakai, D. Johnstone, F. Menard, Y. Aikawa, M. Bouvier, G. Sabatini, A. Miotello, C. Vastel, N. Cuello, E. Bianchi, P. Caselli, E. Caux, T. Hanawa, E. Herbst, D. Segura-Cox, Z. Zhang, S. Yamamoto

Comments: Accepted in A&A Letters

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)

Context. Understanding the connection between outflows, winds, accretion and disks in the inner protostellar regions is crucial for comprehending star and planet formation process. Aims. We aim to we explore the inner 300 au of the protostar IRAS 4A2 as part of the ALMA FAUST Large Program. Methods. We analysed the kinematical structures of SiO and CH$_3$OH emission with 50 au resolution. Results. The emission arises from three zones: i) a very compact and unresolved region ($<$50 au) dominated by the ice sublimation zone, at $\pm$1.5 km s$^{-1}$ with respect to vsys, traced by methanol; ii) an intermediate region (between 50 au and 150 au) traced by both SiO and CH$_3$OH, between 2 and 6 km s$^{-1}$ with respect to vsys, with an inverted velocity gradient (with respect to the large scale emission), whose origin is not clear; iii) an extended region ($>$150 au) traced by SiO, above 7 km s$^{-1}$ with respect to vsys, and dominated by the outflow. In the intermediate region we estimated a CH$_3$OH/SiO abundance ratio of about 120-400 and a SiO/H$_2$ abundance of 10$^{-8}$. We explored various possibilities to explain the origin of this region such as, rotating disk/inner envelope, jet on the plane of the sky/precessing, wide angle disk wind. Conclusions. We propose that CH$_3$OH and SiO in the inner 100 au probe the base of a wide-angle disk wind. The material accelerated in the wind crosses the plane of the sky, giving rise to the observed inverted velocity gradient, and sputtering the grain mantles and cores releasing CH$_3$OH and SiO. This is the first detection of a disk wind candidate in SiO, and the second ever in CH$_3$OH.

[55]  arXiv:2404.19691 [pdf, other]

Title: Optical ray tracing of echelle spectrographs applied to the wavelength solution for precise radial velocities

Authors: Marcelo Tala Pinto, Adrian Kaminski, Andreas Quirrenbach, Mathias Zechmeister

Journal-ref: J. Astron. Telesc. Instrum. Syst. 10(2), 028001 (2024)

Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)

We present $\texttt{moes}$, a ray tracing software package that computes the path of rays through echelle spectrographs. Our algorithm is based on sequential direct tracing with Seidel aberration corrections applied at the detector plane. As a test case, we model the CARMENES VIS spectrograph. After subtracting the best model from the data, the residuals yield an rms of 0.024 pix, setting a new standard to the precision of the wavelength solution of state-of-the-art radial velocity instruments. By including the influence of the changes of the environment in the ray propagation, we are able to predict instrumental radial velocity systematics at the 1 m/s level.

[56]  arXiv:2404.19694 [pdf, other]

Title: Scalar perturbations from inflation in the presence of gauge fields

Authors: R. Durrer, R. von Eckardstein, Deepen Garg, K. Schmitz, O. Sobol, S. Vilchinskii

Comments: 36 pages, 5 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)

We study how Abelian-gauge-field production during inflation affects scalar perturbations in the case when the gauge field interacts with the inflaton directly (by means of generic kinetic and axial couplings) and via gravity. The homogeneous background solution is defined by self-consistently taking into account the backreaction of the gauge field on the evolution of the inflaton and the scale factor. For the perturbations on top of this background, all possible scalar contributions coming from the inflaton, the metric, and the gauge field are considered. We derive a second-order differential equation for the curvature perturbation, $\zeta$, capturing the impact of the gauge field, both on the background dynamics and on the evolution of scalar perturbations. The latter is described by a source term in the $\zeta$-equation, which is quadratic in the gauge-field operators and leads to non-Gaussianities in the curvature perturbations. We derive general expressions for the induced scalar power spectrum and bispectrum. Finally, we apply our formalism to the well-known case of axion inflation without backreaction. Numerical results show that, in this example, the effect of including metric perturbations is small for values of the gauge-field production parameter $\xi> 3$. This is in agreement with the results of previous studies in the literature. However, in the region of smaller values, $\xi\lesssim 2$, our new results exhibit order-of-unity deviations when compared to previous results.

[57]  arXiv:2404.19709 [pdf, other]

Title: SRG/ART-XC discovery of SRGAJ144459.2-604207: a well-tempered bursting accreting millisecond X-ray pulsar

Authors: S.V. Molkov (1), A.A.Lutovinov (1), S.S. Tsygankov (2), V.F. Suleimanov (3), J. Poutanen (2), I.Yu. Lapshov (1), I.A. Mereminskiy (1), A.N. Semena (1), V.A. Arefiev (1), A.Yu. Tkachenko (1) ((1) Space Research Institute of Russian Academy of Sciences, Moscow, (2) Department of Physics and Astronomy, University of Turku, Finland, (3) Institut fur Astronomie und Astrophysik, Universitat Tubingen, Germany)

Comments: 8 pages, 13 figures, 1 table

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

We report on the discovery of the new accreting millisecond X-ray pulsar SRGAJ144459.2-604207 using the SRG/ART-XC data. The source was observed twice in February 2024 during the declining phase of the outburst. Timing analysis revealed a coherent signal near 447.8~Hz modulated by the Doppler effect due to the orbital motion. The derived parameters for the binary system are consistent with the circular orbit with a period of $\sim5.2$~h. The pulse profiles of the persistent emission, showing a sine-like part during half a period with a plateau in between, can well be modelled by emission from two circular spots partially eclipsed by the accretion disk. Additionally, during our 133~ks exposure observations, we detected 19 thermonuclear X-ray bursts. All bursts have similar shapes and energetics, and do not show any signs of photospheric radius expansion. The burst rate decreases linearly from one per $\sim$1.6~h at the beginning of observations to one per $\sim$2.2~h at the end and anticorrelates with the persistent flux. Spectral evolution during the bursts is consistent with the models of the neutron star atmospheres heated by accretion and imply a neutron star radius of 11--12~km and the distance to the source of 8--9~kpc. We also detected pulsations during the bursts and showed that the pulse profiles differ substantially from those observed in the persistent emission. However, we could not find a simple physical model explaining the pulse profiles detected during the bursts.

[58]  arXiv:2404.19730 [pdf, other]

Title: Investigating the correlations between IceCube high-energy neutrinos and Fermi-LAT $γ$-ray observations. II

Authors: Ming-Xuan Lu, Yun-Feng Liang, Xuerui Ouyang, Rong-Lan Li, Xiang-Gao Wang

Comments: Prepared for submission, comments are welcome

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Given that gamma rays with energies larger than TeV are severely absorbed by background radiation fields, for many extragalactic sources, the GeV-TeV gamma-ray observations are the messengers that are closest in energy to the TeV-PeV neutrinos observed by IceCube. Investigating whether there is a correlation between the gamma-ray and neutrino observations can help us identify high-energy neutrino sources and determine which sources are the main contributors to the all-sky diffuse neutrino flux of IceCube. In previous work, we have already studied the possible gamma-neutrino correlations by analyzing 10 years of IceCube muon-track data. In this work, we further investigate such correlations by employing the IceCube p-value sky map of the scan for point sources. We examine the spatial associations of hotspots in the neutrino sky map with various gamma-ray source samples: the third Fermi-LAT catalog of high-energy sources (3FHL), LAT 14-year source catalog (4FGL), the fourth catalog of active galactic nuclei (4LAC) and subsets of these samples. Among all the samples, the 3FHL sample shows a possible correlation with the neutrino hotspots, with a pre-trial p-value of $1.1\times10^{-4}$ ($\sim 3.9\,\sigma$). However, this is found to be caused by three already known neutrino sources/source candidates: NGC 1068, TXS 0506+056, and PKS 1424+240. In order to validate our analysis procedure and to test the robustness of the previously claimed correlation between the 5BZCAT blazars and neutrino hotspots, we also consider 5BZCAT blazars in our correlation study. We find that the way in which mock sources are generated in the simulation used to derive the chance coincidence probability may have a large impact on the claimed correlation.

[59]  arXiv:2404.19732 [pdf, other]

Title: An evaluation of the BALROG and RoboBA algorithms for determining the position of Fermi/GBM GRBs

Authors: K. Océlotl. C. López, Alan M. Watson, William H. Lee, Rosa L. Becerra, Margarita Pereyra

Comments: Revision sent to MNRAS after addressing minimal referee comments

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

The Fermi/GBM instrument is a vital source of detections of gamma-ray bursts and has an increasingly important role to play in understanding gravitational-wave transients. In both cases, its impact is increased by accurate positions with reliable uncertainties. We evaluate the RoboBA and BALROG algorithms for determining the position of gamma-ray bursts detected by the Fermi/GBM instrument. We construct a sample of 54 bursts with detections both by Swift/BAT and by Fermi/GBM. We then compare the positions predicted by RoboBA and BALROG with the positions measured by BAT, which we can assume to be the true position. We find that RoboBA and BALROG are similarly precise for bright bursts whose uncertainties are dominated by systematic errors, but RoboBA performs better for faint bursts whose uncertainties are dominated by statistical noise. We further find that the uncertainties in the positions predicted by RoboBA are consistent with the distribution of position errors, whereas BALROG seems to be underestimating the uncertainties by a factor of about two. Additionally, we consider the implications of these results for the follow-up of the optical afterglows of Fermi/GBM bursts. In particular, for the DDOTI wide-field imager we conclude that a single pointing is best. Our sample would allow a similar study to be carried out for other telescopes.

[60]  arXiv:2404.19742 [pdf, other]

Title: Testing the accuracy of SED modeling techniques using the NIHAO-SKIRT-Catalog

Authors: Nicholas Faucher, Michael R. Blanton

Subjects: Astrophysics of Galaxies (astro-ph.GA)

We use simulated galaxy observations from the NIHAO-SKIRT-Catalog to test the accuracy of Spectral Energy Distribution (SED) modeling techniques. SED modeling is an essential tool for inferring star-formation histories from nearby galaxy observations, but is fraught with difficulty due to our incomplete understanding of stellar populations, chemical enrichment processes, and the nonlinear, geometry-dependent effects of dust on our observations. The NIHAO-SKIRT-Catalog uses hydrodynamic simulations and radiative transfer to produce SEDs from the ultraviolet (UV) through the infrared (IR), accounting for the effects of dust. We use the commonly used Prospector software to perform inference on these SEDs, and compare the inferred stellar masses and star-formation rates (SFRs) to the known values in the simulation. We match the stellar population models to isolate the effects of differences in the star-formation history, the chemical evolution history, and the dust. We find that the combined effect of model mismatches for high mass ($> 10^{9.5} M_{\odot}$) galaxies leads to inferred SFRs that are on average underestimated by a factor of 2 when fit to UV through IR photometry, and a factor of 3 when fit to UV through optical photometry. These biases lead to significant inaccuracies in the resulting sSFR-mass relations, with UV through optical fits showing particularly strong deviations from the true relation of the simulated galaxies. In the context of massive existing and upcoming photometric surveys, these results highlight that star-formation history inference from photometry remains imprecise and inaccurate, and that there is a pressing need for more realistic testing of existing techniques.

Cross-lists for Wed, 1 May 24

[61]  arXiv:2404.19012 (cross-list from gr-qc) [pdf, other]

Title: Neutron stars and the cosmological constant problem

Authors: Giulia Ventagli, Pedro G. S. Fernandes, Andrea Maselli, Antonio Padilla, Thomas P. Sotiriou

Comments: 21 pages, 15 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

Phase transitions can play an important role in the cosmological constant problem, allowing the underlying vacuum energy, and therefore the value of the cosmological constant, to change. Deep within the core of neutron stars, the local pressure may be sufficiently high to trigger the QCD phase transition, thus generating a shift in the value of the cosmological constant. The gravitational effects of such a transition should then be imprinted on the properties of the star. Working in the framework of General Relativity, we provide a new model of the stellar interior, allowing for a QCD and a vacuum energy phase transition. We determine the impact of a vacuum energy jump on mass-radius relations, tidal deformability-radius relations, I-Love-Q relations and on the combined tidal deformability measured in neutron star binaries.

[62]  arXiv:2404.19046 (cross-list from gr-qc) [pdf, ps, other]

Title: Peculiar velocities in Friedmann universes with nonzero spatial curvature

Authors: Eleftheria P. Miliou, Christos G. Tsagas

Comments: 15 pages, 1 figure

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

We extend the earlier linear studies of cosmological peculiar velocities to Friedmann universes with nonzero spatial curvature. In the process, we also compare our results with those obtained in cosmologies with Euclidean spatial sections. Employing relativistic cosmological perturbation theory, we first provide the differential formulae governing the evolution of peculiar velocities on all Friedmann backgrounds. The technical complexities of the curved models, however, mean that analytic solutions are possible only in special, though characteristic, moments in the lifetime of these universes. Nevertheless, our solutions exhibit persistent patterns that make us confident enough to generalise them. Thus, we confirm earlier claims that, compared to the Newtonian studies, the relativistic analysis supports considerably stronger linear growth-rates for peculiar-velocity perturbations. This result holds irrespective of the background curvature. Moreover, for positive curvature, the peculiar growth-rate is found to be faster than that obtained in a spatially flat Friedman universe. In contrast, linear peculiar velocities appear to grow at a slower pace when their Friedmann host is spatially open. Extrapolating them to the present, our results seem to suggest faster bulk peculiar motions in overdense, rather than in underdense, regions of the universe.

[63]  arXiv:2404.19108 (cross-list from cs.CV) [pdf, other]

Title: Real-Time Convolutional Neural Network-Based Star Detection and Centroiding Method for CubeSat Star Tracker

Authors: Hongrui Zhao, Michael F. Lembeck, Adrian Zhuang, Riya Shah, Jesse Wei

Subjects: Computer Vision and Pattern Recognition (cs.CV); Instrumentation and Methods for Astrophysics (astro-ph.IM); Image and Video Processing (eess.IV)

Star trackers are one of the most accurate celestial sensors used for absolute attitude determination. The devices detect stars in captured images and accurately compute their projected centroids on an imaging focal plane with subpixel precision. Traditional algorithms for star detection and centroiding often rely on threshold adjustments for star pixel detection and pixel brightness weighting for centroid computation. However, challenges like high sensor noise and stray light can compromise algorithm performance. This article introduces a Convolutional Neural Network (CNN)-based approach for star detection and centroiding, tailored to address the issues posed by noisy star tracker images in the presence of stray light and other artifacts. Trained using simulated star images overlayed with real sensor noise and stray light, the CNN produces both a binary segmentation map distinguishing star pixels from the background and a distance map indicating each pixel's proximity to the nearest star centroid. Leveraging this distance information alongside pixel coordinates transforms centroid calculations into a set of trilateration problems solvable via the least squares method. Our method employs efficient UNet variants for the underlying CNN architectures, and the variants' performances are evaluated. Comprehensive testing has been undertaken with synthetic image evaluations, hardware-in-the-loop assessments, and night sky tests. The tests consistently demonstrated that our method outperforms several existing algorithms in centroiding accuracy and exhibits superior resilience to high sensor noise and stray light interference. An additional benefit of our algorithms is that they can be executed in real-time on low-power edge AI processors.

[64]  arXiv:2404.19191 (cross-list from hep-ph) [pdf, other]

Title: High-energy neutrino signals from supernova explosions: a new window into dark photon parameter space

Authors: Vsevolod Syvolap, Oleg Ruchayskiy

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)

Dark photons, hypothetical feebly interacting massive vector bosons, appear in many extensions of the Standard Model. This study investigates their production and subsequent decay during supernova explosions. We demonstrate that the decay of dark photons, with masses ranging from 200 to 400 MeV, can lead to the emission of neutrinos with energies surpassing those emitted by supernovae. These neutrinos therefore serve as a distinct signal of new physics, allowing for the exploration of previously uncharted regions of the dark photon parameter space and complementing both accelerator-based searches and other astrophysical constraints. The signal is largely unaffected by the specifics of the supernova's temperature and density radial profiles outside the SN core, rendering the prediction both robust and model-independent. Our results indicate that searching for high-energy neutrinos accompanying supernova explosions provides a novel approach to probe physics beyond the Standard Model, including dark photons, heavy neutral leptons, and other feebly interacting particles with masses in the hundreds of MeV range.

[65]  arXiv:2404.19285 (cross-list from physics.plasm-ph) [pdf, other]

Title: Three-dimensional plasmoid-mediated reconnection and turbulence in Hall magnetohydrodynamics

Authors: Yi-Min Huang, Amitava Bhattacharjee

Subjects: Plasma Physics (physics.plasm-ph); Solar and Stellar Astrophysics (astro-ph.SR); Space Physics (physics.space-ph)

Plasmoid instability accelerates reconnection in collisional plasmas by transforming a laminar reconnection layer into numerous plasmoids connected by secondary current sheets in two dimensions (2D) and by fostering self-generated turbulent reconnection in three dimensions (3D). In large-scale astrophysical and space systems, plasmoid instability likely initiates in the collisional regime but may transition into the collisionless regime as the fragmentation of the current sheet progresses toward kinetic scales. Hall MHD models are widely regarded as a simplified yet effective representation of the transition from collisional to collisionless reconnection. However, plasmoid instability in 2D Hall MHD simulations often leads to a single-X-line reconnection configuration, which significantly differs from fully kinetic particle-in-cell simulation results. This study shows that single-X-line reconnection is less likely to occur in 3D compared to 2D. Moreover, depending on the Lundquist number and the ratio between the system size and the kinetic scale, Hall MHD can also realize 3D self-generated turbulent reconnection. We analyze the features of the self-generated turbulent state, including the energy power spectra and the scale dependence of turbulent eddy anisotropy.

[66]  arXiv:2404.19498 (cross-list from gr-qc) [pdf, other]

Title: Into the MAG-verse or: Cosmology of the Complete Quadratic Metric-Affine Gravity

Authors: Damianos Iosifidis, Konstantinos Pallikaris

Comments: 29 pages, 2 figures, PDF with matrix coefficients included

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

We study the cosmology of the complete quadratic (in torsion and nonmetricity) metric-affine gravity. Namely, we add to the scalar-curvature gravitational Lagrangian, the 17 independent quadratic (parity-even and parity-odd) torsion and nonmetricity invariants. Sticking to a homogeneous and isotropic Friedmann-Robertson-Walker spacetime and assuming a perfect hyperfluid source, we explore the new effects that torsion and nonmetricity bring into play. It is shown that the inclusion of these invariants offers rich phenomenology. In particular, some well-known examples of exotic matter like cosmic strings, domain walls, stiff matter, etc., emerge quite naturally as manifestations of the fluid's intrinsic structure (hypermomentum). By studying the extended Friedmann equations in the complete quadratic theory and isolating the various parts of the hypermomentum, we find a plethora of solutions with interesting features.

[67]  arXiv:2404.19726 (cross-list from hep-ph) [pdf, other]

Title: On the inefficiency of fermion level-crossing under the parity-violating spin-2 gravitational field

Authors: Kohei Kamada, Jun'ya Kume

Comments: 34 pages, 5 figures

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

Gravitational chiral anomaly connects the topological charge of spacetime and the chirality of fermions. It has been known that the chirality is carried by the particles (or the excited states) and also by vacuum. While the gravitational anomaly equation has been applied to cosmology, distinction between these two contributions has been rarely discussed. In the study of gravitational leptogenesis, for example, lepton asymmetry associated with the chiral gravitational waves sourced during inflation is evaluated only by integrating the anomaly equation. How these two contributions are distributed has not been seriously investigated. Meanwhile, a dominance of vacuum contribution is observed in some specific types of Bianchi spacetime with parity-violating gravitational fields, whose application to cosmology is not straightforward. One may wonder whether such a vacuum dominance takes place also in the system with chiral gravitational waves around the flat background, which is more suitable for application to realistic cosmology. In this work, we apply an analogy between U(1) electromagnetism and the weak gravity to the spacetime that resembles the one considered in the gravitational leptogenesis scenario. This approach allows us to obtain intuitive understanding of the fermion chirality generation under the parity-violating spin-2 gravitational field. By assuming the emergence of Landau level-like dispersion relation in our setup, we conjecture that level-crossing does not seem to be efficient while the charge accumulation in the vacuum likely takes place. Phenomenological implication is also discussed in the context of gravitational leptogenesis.

Replacements for Wed, 1 May 24

[68]  arXiv:2202.08899 (replaced) [pdf, ps, other]

Title: ROME III. The Arecibo Search for Star-Planet Interactions at 5 GHz

Authors: Matthew Route (1,2,3), Alex Wolszczan (1) ((1) Pennsylvania State University, (2) Northrop Grumman Electronic Systems, (3) University of Mississippi)

Comments: 16 pages, 4 tables, 3 figures

Journal-ref: ApJ, 952, 118 (2023)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

[69]  arXiv:2204.08732 (replaced) [pdf, other]

Title: On the detection and precise localisation of merging black holes events through strong gravitational lensing

Authors: Ewoud Wempe, Léon V. E. Koopmans, A. Renske A. C. Wierda, Otto Akseli Hannuksela, Chris van den Broeck

Comments: 23 pages, 14 figures, 3 tables. Accepted for publication in MNRAS

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)

[70]  arXiv:2210.02707 (replaced) [pdf, ps, other]

Title: Assisted baryon number violation from $4k+2$ dimensions

Authors: Akshay A, Mathew Thomas Arun

Comments: 32 pages, 2 figures, Accepted for publication in PRD

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[71]  arXiv:2211.06434 (replaced) [pdf, other]

Title: Plasmoid Instability in the Multiphase Interstellar Medium

Authors: Drummond B. Fielding, Bart Ripperda, Alexander A. Philippov

Comments: 21 pages, 13 figures. For associated movies, see this https URL

Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

[72]  arXiv:2211.13608 (replaced) [pdf, other]

Title: Inference of cosmological models with principal component analysis

Authors: Ranbir Sharma, H K Jassal

Comments: 27 pages, 18 figures

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[73]  arXiv:2303.06125 (replaced) [pdf, other]

Title: 3D hydrodynamic simulations of massive main-sequence stars II. Convective excitation and spectra of internal gravity waves

Authors: William Thompson, Falk Herwig, Paul R. Woodward, Huaqing Mao, Pavel Denissenkov, Dominic M. Bowman, Simon Blouin

Comments: Accepted version (2024 April 26). Originally submitted 2022 November 04

Subjects: Solar and Stellar Astrophysics (astro-ph.SR)

[74]  arXiv:2306.06172 (replaced) [pdf, other]

Title: Reconstruction of Cosmic Black Hole Growth and Mass Distribution from Quasar Luminosity Functions at $z>4$: Implications for Faint and Low-mass Populations in JWST

Authors: Wenxiu Li, Kohei Inayoshi, Masafusa Onoue, Wanqiu He, Yoshiki Matsuoka, Zhiwei Pan, Masayuki Akiyama, Takuma Izumi, Tohru Nagao

Comments: 16 pages, 8 figures; Accepted by ApJ

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[75]  arXiv:2308.08540 (replaced) [pdf, other]

Title: Most of the photons that reionized the Universe came from dwarf galaxies

Authors: Hakim Atek, Ivo Labbé, Lukas J. Furtak, Iryna Chemerynska, Seiji Fujimoto, David J. Setton, Tim B. Miller, Pascal Oesch, Rachel Bezanson, Sedona H. Price, Pratika Dayal, Adi Zitrin, Vasily Kokorev, John R. Weaver, Gabriel Brammer, Pieter van Dokkum, Christina C. Williams, Sam E. Cutler, Robert Feldmann, Yoshinobu Fudamoto, Jenny E. Greene, Joel Leja, Michael V. Maseda, Adam Muzzin, Richard Pan, Casey Papovich, Erica J. Nelson, Themiya Nanayakkara, Daniel P. Stark, Mauro Stefanon, Katherine A. Suess, Bingjie Wang, Katherine E. Whitaker

Comments: 29 pages, 7 figures, 2 tables. Published in Nature

Journal-ref: Nature Volume 626, 2024, 975-978

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[76]  arXiv:2309.02330 (replaced) [pdf, other]

Title: The viability of low-mass subhaloes as targets for gamma-ray dark matter searches

Authors: Alejandra Aguirre-Santaella, Miguel A. Sánchez-Conde

Comments: 16 pages, 16 figures. Accepted in MNRAS; matches published version

Journal-ref: Monthly Notices of the Royal Astronomical Society, Volume 530, Issue 3, May 2024, Pages 2496-2511

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)

[77]  arXiv:2309.07949 (replaced) [pdf, other]

Title: Compositional metrics of fast and slow Alfvenic solar wind emerging from coronal holes and their boundaries

Authors: Tamar Ervin, Stuart D. Bale, Samuel T. Badman, Yeimy J. Rivera, Orlando Romeo, Jia Huang, Pete Riley, Trevor A. Bowen, Susan T. Lepri, Ryan M. Dewey

Comments: 23 pages, 10 figures

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Space Physics (physics.space-ph)

[78]  arXiv:2309.14993 (replaced) [pdf, other]

Title: Induced gravitational waves and baryon asymmetry fluctuations from primordial black hole formation

Authors: Chiara Altavista, Julián Rey

Comments: 40 pages, 12 figures. Minor clarifications, version accepted for publication in JCAP

Journal-ref: JCAP 04 (2024) 052

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)

[79]  arXiv:2309.16944 (replaced) [pdf, other]

Title: Image of Kerr-de Sitter black holes illuminated by equatorial thin accretion disks

Authors: Ke Wang, Chao-Jun Feng, Towe Wang

Comments: 17 pages, 10 figures, refs added, typos corrected

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[80]  arXiv:2311.02161 (replaced) [pdf, other]

Title: Parity violation in gravitational waves and observational bounds from third-generation detectors

Authors: Matteo Califano, Rocco D'Agostino, Daniele Vernieri

Comments: 19 pages, 8 figures. Accepted for publication in Phys. Rev. D

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)

[81]  arXiv:2311.05364 (replaced) [pdf, other]

Title: First upper limits on the 21 cm signal power spectrum from cosmic dawn from one night of observations with NenuFAR

Authors: S. Munshi, F. G. Mertens, L. V. E. Koopmans, A. R. Offringa, B. Semelin, D. Aubert, R. Barkana, A. Bracco, S. A. Brackenhoff, B. Cecconi, E. Ceccotti, S. Corbel, A. Fialkov, B. K. Gehlot, R. Ghara, J. N. Girard, J. M. Grießmeier, C. Höfer, I. Hothi, R. Mériot, M. Mevius, P. Ocvirk, A. K. Shaw, G. Theureau, S. Yatawatta, P. Zarka, S. Zaroubi

Comments: 27 pages, 21 figures, and 6 tables; accepted for publication in Astronomy and Astrophysics (A&A); language edits implemented; typos corrected

Journal-ref: A&A 681, A62 (2024)

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM)

[82]  arXiv:2311.05439 (replaced) [pdf, other]

Title: Final Results of Search for New Milky Way Satellites in the Hyper Suprime-Cam Subaru Strategic Program Survey: Discovery of Two More Candidates

Authors: Daisuke Homma, Masashi Chiba, Yutaka Komiyama, Masayuki Tanaka, Sakurako Okamoto, Mikito Tanaka, Miho N. Ishigaki, Kohei Hayashi, Nobuo Arimoto, Robert H. Lupton, Michael A. Strauss, Satoshi Miyazaki, Shiang-Yu Wang, Hitoshi Murayama

Comments: 20 pages, 17 figures, 4 tables, accepted for publication in PASJ

Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[83]  arXiv:2311.13805 (replaced) [pdf, other]

Title: Mass and radius of the most massive neutron star: The probe of the equation of state and perturbative QCD

Authors: Shao-Peng Tang, Ming-Zhe Han, Yong-Jia Huang, Yi-Zhong Fan, Da-Ming Wei

Comments: 12 pages, 5 figures, PRD published

Journal-ref: Phys. Rev. D 109, 083037 (2024)

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)

[84]  arXiv:2312.02645 (replaced) [pdf, other]

Title: Constraints on UHECR sources and extragalactic magnetic fields from directional anisotropies

Authors: Teresa Bister, Glennys R. Farrar

Journal-ref: ApJ 966 71 (2024)

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[85]  arXiv:2312.02707 (replaced) [pdf, ps, other]

Title: SKA Sensitivity to Sub-GeV Dark Matter Decay: Synchrotron Radio Emissions in White Dwarf Magnetospheres

Authors: Kenji Kadota, Shota Kisaka

Comments: 10 pages, 4 figures

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)

[86]  arXiv:2401.08162 (replaced) [pdf, other]

Title: A New Window for Studying Intermediate Polars and Tilted Accretion Disk Precession

Authors: Qi-Bin Sun, Sheng-Bang Qian, Li-Ying Zhu, Wen-Ping Liao, Er-Gang Zhao, Fu-Xing Li, Xiang-Dong Shi, Min-Yu Li

Comments: 18 pages, 7 figures, 3 tables; Accepted for publication in The Astrophysical Journal

Subjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)

[87]  arXiv:2401.08288 (replaced) [pdf, other]

Title: Finding origins of CMB anomalies in the inflationary quantum fluctuations

Authors: Enrique Gaztañaga, K. Sravan Kumar

Comments: 63 pages, 22 figures, version accepted for publication in JCAP

Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

[88]  arXiv:2401.08952 (replaced) [pdf, other]

Title: The past and future 20-years endeavor for discovering origins of ultra-high energy cosmic rays -- Rapporteur's summary of cosmic ray indirect --

Authors: Toshihiro Fujii

Comments: 24 pages, 11 figures, Rapporteur talk in the 38th International Cosmic Ray Conference (ICRC2023)

Journal-ref: PoS (ICRC2023) 031

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)

[89]  arXiv:2401.12684 (replaced) [pdf, ps, other]

Title: Energy self-extraction of a Kerr black hole with the force-free magnetosphere frame-dragged

Authors: Isao Okamoto, Toshio Uchida, Yoogeun Song

Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

[90]  arXiv:2402.06000 (replaced) [pdf, other]

Title: The Rise and Fall of the Standard-Model Higgs: Electroweak Vacuum Stability during Kination

Authors: Giorgio Laverda, Javier Rubio

Comments: 20 pages, 8 figures, updated constraints and figures

Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc)

[91]  arXiv:2402.08366 (replaced) [pdf, other]

Title: Small-scale dynamo with nonzero correlation time

Authors: Kishore Gopalakrishnan, Nishant K Singh

Comments: 20 pages, 3 figures, 1 table. Version incorporating referees' comments. Major changes: in section 3.3, pointed out an oversight in a previous work that explains some qualitative differences in the final evolution equation; discussed the validity of WKB; fixed a mistake in section 4.2.5 (that does not affect the final results); clarified the use of equation 13 based on a comment received

Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR); Plasma Physics (physics.plasm-ph)

[92]  arXiv:2402.09857 (replaced) [pdf, ps, other]

Title: Predicting the Ages of Galaxies with an Artificial Neural Network

Authors: Laura. J. Hunt, Kevin. A. Pimbblet, David. M. Benoit

Comments: 20 pages, 19 figures, Published in MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[93]  arXiv:2402.14089 (replaced) [pdf, other]

Title: The Origin of the Slow-to-Alfvén Wave Cascade Power Ratio and its Implications for Particle Heating in Accretion Flows

Authors: Kaushik Satapathy, Dimitrios Psaltis, Feryal Özel

Comments: Accepted for publication in ApJ

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Plasma Physics (physics.plasm-ph)

[94]  arXiv:2403.02226 (replaced) [pdf, other]

Title: ROME IV. The Arecibo Search for Substellar Magnetospheric Radio Emissions in Purported Exoplanet-Hosting Systems at 5 GHz

Authors: Matthew Route (1,2,3) ((1) Pennsylvania State University, (2) Northrop Grumman Electronic Systems, (3) University of Mississippi)

Comments: 18 pages, 4 tables, 2 figures

Journal-ref: ApJ, 966, 55 (2024)

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

[95]  arXiv:2403.12169 (replaced) [pdf, other]

Title: Photo-production of axions in Supernovae

Authors: Sabyasachi Chakraborty, Aritra Gupta, Miguel Vanvlasselaer

Comments: 10 pages, 5 figures, Appendix

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)

[96]  arXiv:2403.15252 (replaced) [pdf, ps, other]

Title: The cause of the difference in the propagation distances between compact and transient jets in black-hole X-ray binaries

Authors: Andrzej A. Zdziarski, Sebastian Heinz

Comments: ApJL, in press

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[97]  arXiv:2403.15519 (replaced) [pdf, ps, other]

Title: Generation of narrow beams of super high-energy gamma quanta in the resonant inverse Compton-effect in the field of a strong x-ray wave

Authors: Sergei P. Roshchupkin, Sergey B. Makarov

Comments: 31 pages, 9 figures, 5 tables

Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)

[98]  arXiv:2404.05354 (replaced) [pdf, other]

Title: Search for Neutrino Emission from GRB 221009A using the KM3NeT ARCA and ORCA detectors

Authors: S. Aiello, A. Albert, M. Alshamsi, S. Alves Garre, A. Ambrosone, F. Ameli, M. Andre, E. Androutsou, M. Anguita, L. Aphecetche, M. Ardid, S. Ardid, H. Atmani, J. Aublin, F. Badaracco, L. Bailly-Salins, Z. Bardačová, B. Baret, A. Bariego-Quintana, S. Basegmez du Pree, Y. Becherini, M. Bendahman, F. Benfenati, M. Benhassi, D. M. Benoit, E. Berbee, V. Bertin, S. Biagi, M. Boettcher, D. Bonanno, J. Boumaaza, M. Bouta, M. Bouwhuis, C. Bozza, R. M. Bozza, H.Brânzaş, F. Bretaudeau, M. Breuhaus, R. Bruijn, J. Brunner, R. Bruno, E. Buis, R. Buompane, J. Busto, B. Caiffi, D. Calvo, S. Campion, A. Capone, F. Carenini, V. Carretero, T. Cartraud, P. Castaldi, V. Cecchini, S. Celli, L. Cerisy, M. Chabab, M. Chadolias, A. Chen, S. Cherubini, T. Chiarusi, M. Circella, R. Cocimano, J. A. B. Coelho, et al. (213 additional authors not shown)

Comments: 11 pages, 2 PDF figures. Submitted to JCAP

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

[99]  arXiv:2404.07782 (replaced) [pdf, other]

Title: Gravitational-wave lensing in Einstein-aether theory

Authors: Julius Streibert, Hector O. Silva, Miguel Zumalacárregui

Comments: 19 pages plus appendices, 4 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)

[100]  arXiv:2404.08574 (replaced) [pdf, other]

Title: Cosmic variance of the Hellings and Downs correlation for ensembles of universes having non-zero angular power spectra

Authors: Deepali Agarwal, Joseph D. Romano

Comments: 13 pages, 2 figures

Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)

[101]  arXiv:2404.09015 (replaced) [pdf, other]

Title: On the universal validity of Case B recombination theory

Authors: C. Scarlata, M. Hayes, N. Panagia, V. Mehta, F. Haardt, M. Bagley

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[102]  arXiv:2404.09511 (replaced) [pdf, other]

Title: Bayesian inference of neutron-skin thickness and neutron-star observables based on effective nuclear interactions

Authors: Jia Zhou, Jun Xu

Comments: 10 pages, 7 figures

Subjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)

[103]  arXiv:2404.10755 (replaced) [pdf, other]

Title: A Young Super Star Cluster Powering a Nebula of Retained Massive Star Ejecta

Authors: Massimo Pascale, Liang Dai

Comments: 23 pages, 12 figures. Updated to match version submitted to ApJ. Comments welcome!

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[104]  arXiv:2404.11892 (replaced) [pdf, other]

Title: Dark supernova remnant buried in the Galactic-Centre "Brick" G0.253+0.016 revealed by an expanding CO-line bubble

Authors: Yoshiaki Sofue

Comments: 15 pages, 9 figures, 1 table, submitted to PASJ Jan.7, 2024

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[105]  arXiv:2404.16345 (replaced) [pdf, other]

Title: WISDOM Project -- XIX. Figures of merit for supermassive black hole mass measurements using molecular gas and/or megamaser kinematics

Authors: Hengyue Zhang, Martin Bureau, Mark D. Smith, Michele Cappellari, Timothy A. Davis, Pandora Dominiak, Jacob S. Elford, Fu-Heng Liang, Ilaria Ruffa, Thomas G. Williams

Comments: 13 pages, 9 figures. Accepted by MNRAS

Subjects: Astrophysics of Galaxies (astro-ph.GA)

[106]  arXiv:2404.16832 (replaced) [pdf, ps, other]

Title: The Black-Hole Masses of High-Redshift QSOs

Authors: Andrew King

Comments: Accepted for MNRAS. Missing reference added

Subjects: Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE)

[107]  arXiv:2404.17816 (replaced) [pdf, other]

Title: A broken debris cascade as a possible source of hot dust emission in transitioning planet-forming disks

Authors: Niels Swinkels, Carsten Dominik

Comments: To be published in Astronomy & Astrophysics

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

[108]  arXiv:2404.18408 (replaced) [pdf, other]

Title: Low surface brightness galaxies from BASS+MzLS with Machine Learning

Authors: Peng-Liang Du, Wei Du, Bing-Qing Zhang, Zhen-Ping Yi, Min He, Hong Wu

Comments: 20 pages, 11 figures, 1 table, accepted by Research in Astronomy and Astrophysics

Subjects: Astrophysics of Galaxies (astro-ph.GA)

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