arXiv - PHYS - High Energy Astrophysical Phenomena最新文献

{"title":"An Intermediate Luminosity GRB 210210A: The early onset of the external forward shock in the X-ray?","authors":"Rahul Gupta, A. K. Ror, S. B. Pandey, J. Racusin, M. Moss, A. Aryan, N. Klingler, A. J. Castro-Tirado","doi":"arxiv-2409.04871","DOIUrl":"https://doi.org/arxiv-2409.04871","url":null,"abstract":"We have analyzed the prompt and afterglow characteristics of the intermediate\u0000luminosity burst ``GRB 210210A\". Our prompt emission analysis indicates that\u0000GRB 210210A is among the softest long GRBs detected by the Swift-BAT. The\u0000time-integrated prompt emission spectrum of GRB 210210A is aptly described by a\u0000power law function with an exponential cutoff. The spectral peak energy\u0000(E$_{p,z}$) in rest-frame and the E$_{rm gamma, iso}$ for this GRB marginally\u0000satisfy the 2$sigma$ Amati correlation, a common feature observed in\u0000low/intermediate luminosity GRBs. Notably, an early bump is observed in the\u0000Swift-XRT light curve (a rare feature); the optical afterglow light curve, on\u0000the other hand, appears to follow a power law decay. However, due to the lack\u0000of sufficient early optical observations, we cannot completely rule out the\u0000possibility of an early bump in the optical light curve. For the bump observed\u0000in the early X-ray light curve, we calculated parameters such as peak time,\u0000rise time, decay time, and bulk Lorentz factor ($Gamma_{0}$ $sim$ 156), which\u0000perfectly satisfy the correlation between the parameters of the onset of the\u0000afterglow in GRBs. Both the optical and X-ray (including our observations)\u0000light curves exhibit a chromatic break in the late afterglow. Based on the\u0000prompt and afterglow parameters, we confirm that the intermediate luminosity\u0000GRB 210210A favors a collapsar scenario and is possibly powered by a magnetar.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A precessing stellar disk model for superorbital modulations of the gamma-ray binary LS I+61$^{circ}$ 303","authors":"A. M. Chen, J. Takata, Y. W. Yu","doi":"arxiv-2409.04818","DOIUrl":"https://doi.org/arxiv-2409.04818","url":null,"abstract":"Gamma-ray binary LS I+61$^{circ}$ 303 consists of a neutron star orbiting\u0000around a Be star with a period of $P_{rm orb}simeq26.5 {rm d}$. Apart from\u0000orbital modulations, the binary shows long-term flux variations with a\u0000superorbital period of $P_{rm sup}simeq4.6 {rm yrs}$ as seen in nearly all\u0000wavelengths. The origin of this superorbital modulation is still not well\u0000understood. Under the pulsar wind-stellar outflow interaction scenario, we\u0000propose that the superorbital modulations of LS I+61$^{circ}$ 303 could be\u0000caused by the precession of the Be disk. Assuming X-rays arise from synchrotron\u0000radiation of the intrabinary shock, we develop an analytical model to calculate\u0000expected flux modulations over the orbital and superorbital phases. The\u0000asymmetric two-peak profiles in orbital light curves and sinusoidal-like\u0000long-term modulations are reproduced under the precessing disk scenario. The\u0000observed orbital phase drifting of the X-ray peak and our fitting of long-term\u0000X-ray data indicate that the neutron star is likely orbiting around the star\u0000with a small eccentricity and periastron phase around $Phi_{rm p}sim0.6$. We\u0000compare the Corbet diagrams of LS I+61$^{circ}$ 303 with other Be/X-ray\u0000binaries and the linear correlation in the $P_{rm sup}-P_{rm orb}$ diagram\u0000suggests that the precession of the Be disk in LS I+61$^{circ}$ 303 is induced\u0000by the tidal torque of its neutron star companion.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Deeper Look into eFEDS AGN Candidates in Dwarf Galaxies with Chandra","authors":"Adonis A. Sanchez, Amy E. Reines, Akos Bogdan, Ralph P. Kraft","doi":"arxiv-2409.04514","DOIUrl":"https://doi.org/arxiv-2409.04514","url":null,"abstract":"The ability to accurately discern active massive black holes (BHs) in nearby\u0000dwarf galaxies is paramount to understanding the origins and processes of\u0000\"seed\" BHs in the early Universe. We present Chandra X-ray Observatory\u0000observations of a sample of three local dwarf galaxies (M$_{*}$ $leqslant 3\u0000times 10^{9}$ M$_odot$, z $leqslant$ 0.15) previously identified as\u0000candidates for hosting active galactic nuclei (AGN). The galaxies were selected\u0000from the NASA-Sloan Atlas (NSA) with spatially coincident X-ray detections in\u0000the eROSITA Final Equatorial Depth Survey (eFEDS). Our new Chandra data reveal\u0000three X-ray point sources in two of the target galaxies with luminosities\u0000between log(L$_{rm text{2-10 keV}}$ [erg s$^{-1}$]) = 39.1 and 40.4. Our\u0000results support the presence of an AGN in these two galaxies and a ULX in one\u0000of them. For the AGNs, we estimate BH masses of $M_{rm BH} sim 10^{5-6}\u0000M_odot$ and Eddington ratios on the order of $sim 10^{-3}$.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ZTF SN Ia DR2: The diversity and relative rates of the thermonuclear SN population","authors":"G. Dimitriadis, U. Burgaz, M. Deckers, K. Maguire, J. Johansson, M. Smith, M. Rigault, C. Frohmaier, J. Sollerman, L. Galbany, Y. -L. Kim, C. Liu, A. A. Miller, P. E. Nugent, A. Alburai, P. Chen, S. Dhawan, M. Ginolin, A. Goobar, S. L. Groom, L. Harvey, W. D. Kenworthy, S. R. Kulkarni, B. Popovic, R. L. Riddle, B. Rusholme, T. E. Muller-Bravo, J. Nordin, J. H. Terwel, A. Townsend","doi":"arxiv-2409.04200","DOIUrl":"https://doi.org/arxiv-2409.04200","url":null,"abstract":"The Zwicky Transient Facility SN Ia Data Release 2 (ZTF SN Ia DR2) contains\u0000more than 3,000 Type Ia supernovae (SNe Ia), providing the largest homogeneous\u0000low-redshift sample of SNe Ia. Having at least one spectrum per event, this\u0000data collection is ideal for large-scale statistical studies of the\u0000photometric, spectroscopic and host-galaxy properties of SNe Ia, particularly\u0000of the more rare \"peculiar\" subclasses. In this paper, we first present the\u0000method we developed to spectroscopically classify the SNe in the sample, and\u0000the techniques we used to model their multi-band light curves and explore their\u0000photometric properties. We then show a method to distinguish between the\u0000\"peculiar\" subtypes and the normal SNe Ia. We also explore the properties of\u0000their host galaxies and estimate their relative rates, focusing on the\u0000\"peculiar\" subtypes and their connection to the cosmologically useful SNe Ia.\u0000Finally, we discuss the implications of our study with respect to the\u0000progenitor systems of the \"peculiar\" SN Ia events.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-epoch leptohadronic modeling of neutrino source candidate blazar PKS 0735+178","authors":"A. Omeliukh, S. Garrappa, V. Fallah Ramazani, A. Franckowiak, W. Winter, E. Lindfors, K. Nilsson, J. Jormanainen, F. Wierda, A. V. Filippenko, W. Zheng, M. Tornikoski, A. Lähteenmäki, S. Kankkunenand, J. Tammi","doi":"arxiv-2409.04165","DOIUrl":"https://doi.org/arxiv-2409.04165","url":null,"abstract":"The origin of the astrophysical neutrino flux discovered by IceCube remains\u0000largely unknown. Several individual neutrino source candidates were observed.\u0000Among them is the gamma-ray flaring blazar TXS 0506+056. A similar coincidence\u0000of a high-energy neutrino and a gamma-ray flare was found in blazar PKS\u00000735+178. By modeling the spectral energy distributions of PKS 0735+178, we\u0000expect to investigate the physical conditions for neutrino production during\u0000different stages of the source activity. We analyze the multi-wavelength data\u0000during the selected periods of time. Using numerical simulations of radiation\u0000processes in the source, we study the parameter space of one-zone leptonic and\u0000leptohadronic models and find the best-fit solutions that explain the observed\u0000photon fluxes. We show the impact of model parameter degeneracy on the\u0000prediction of the neutrino spectra. We show that the available mutli-wavelength\u0000data are not sufficient to predict the neutrino spectrum unambiguously. Still,\u0000under the condition of maximal neutrino flux, we propose a scenario in which\u00000.2 neutrino events are produced during the 50 days flare.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GRB 221009A: the B.O.A.T Burst that Shines in Gamma Rays","authors":"M. AxelssonFermi LAT collaboration, M. AjelloFermi LAT collaboration, M. ArimotoFermi LAT collaboration, L. BaldiniFermi LAT collaboration, J. BalletFermi LAT collaboration, M. G. BaringFermi LAT collaboration, C. BartoliniFermi LAT collaboration, D. BastieriFermi LAT collaboration, J. Becerra GonzalezFermi LAT collaboration, R. BellazziniFermi LAT collaboration, B. BerenjiFermi LAT collaboration, E. BissaldiFermi LAT collaboration, R. D. BlandfordFermi LAT collaboration, R. BoninoFermi LAT collaboration, P. BruelFermi LAT collaboration, S. BusonFermi LAT collaboration, R. A. CameronFermi LAT collaboration, R. CaputoFermi LAT collaboration, P. A. CaraveoFermi LAT collaboration, E. CavazzutiFermi LAT collaboration, C. C. CheungFermi LAT collaboration, G. ChiaroFermi LAT collaboration, N. CibrarioFermi LAT collaboration, S. CipriniFermi LAT collaboration, G. CozzolongoFermi LAT collaboration, P. Cristarella OrestanoFermi LAT collaboration, M. CrnogorcevicFermi LAT collaboration, A. CuocoFermi LAT collaboration, S. CutiniFermi LAT collaboration, F. D'AmmandoFermi LAT collaboration, S. De GaetanoFermi LAT collaboration, N. Di LallaFermi LAT collaboration, A. DineshFermi LAT collaboration, R. Di TriaFermi LAT collaboration, L. Di VenereFermi LAT collaboration, A. DomínguezFermi LAT collaboration, S. J. FeganFermi LAT collaboration, E. C. FerraraFermi LAT collaboration, A. FioriFermi LAT collaboration, A. FranckowiakFermi LAT collaboration, Y. FukazawaFermi LAT collaboration, S. FunkFermi LAT collaboration, P. FuscoFermi LAT collaboration, G. GalantiFermi LAT collaboration, F. GarganoFermi LAT collaboration, C. GasbarraFermi LAT collaboration, S. GermaniFermi LAT collaboration, F. GiacchinoFermi LAT collaboration, N. GigliettoFermi LAT collaboration, M. GilibertiFermi LAT collaboration, R. GillFermi LAT collaboration, F. GiordanoFermi LAT collaboration, M. GirolettiFermi LAT collaboration, J. GranotFermi LAT collaboration, D. GreenFermi LAT collaboration, I. A. GrenierFermi LAT collaboration, S. GuiriecFermi LAT collaboration, M. GustafssonFermi LAT collaboration, M. HashizumeFermi LAT collaboration, E. HaysFermi LAT collaboration, J. W. HewittFermi LAT collaboration, D. HoranFermi LAT collaboration, T. KayanokiFermi LAT collaboration, M. KussFermi LAT collaboration, A. LavironFermi LAT collaboration, J. LiFermi LAT collaboration, I. LiodakisFermi LAT collaboration, F. LongoFermi LAT collaboration, F. LoparcoFermi LAT collaboration, L. LorussoFermi LAT collaboration, B. LottFermi LAT collaboration, M. N. LovelletteFermi LAT collaboration, P. LubranoFermi LAT collaboration, S. MalderaFermi LAT collaboration, D. MalyshevFermi LAT collaboration, A. ManfredaFermi LAT collaboration, G. Martí-DevesaFermi LAT collaboration, R. MartinelliFermi LAT collaboration, I. Martinez CastellanosFermi LAT collaboration, M. N. MazziottaFermi LAT collaboration, J. E. McEneryFermi LAT collaboration, I. MereuFermi LAT collaboration, M. MeyerFermi LAT collaboration, P. F. MichelsonFermi LAT collaboration, N. MirabalFermi LAT collaboration, W. MitthumsiriFermi LAT collaboration, T. MizunoFermi LAT collaboration, P. Monti-GuarnieriFermi LAT collaboration, M. E. MonzaniFermi LAT collaboration, T. MorishitaFermi LAT collaboration, A. MorselliFermi LAT collaboration, I. V. MoskalenkoFermi LAT collaboration, M. NegroFermi LAT collaboration, R. NiwaFermi LAT collaboration, N. OmodeiFermi LAT collaboration, M. OrientiFermi LAT collaboration, E. OrlandoFermi LAT collaboration, D. PanequeFermi LAT collaboration, G. PanzariniFermi LAT collaboration, M. PersicFermi LAT collaboration, M. Pesce-RollinsFermi LAT collaboration, V. PetrosianFermi LAT collaboration, R. PilleraFermi LAT collaboration, F. PironFermi LAT collaboration, T. A. PorterFermi LAT collaboration, G. PrincipeFermi LAT collaboration, J. L. RacusinFermi LAT collaboration, S. RainòFermi LAT collaboration, R. RandoFermi LAT collaboration, B. RaniFermi LAT collaboration, M. RazzanoFermi LAT collaboration, S. RazzaqueFermi LAT collaboration, A. ReimerFermi LAT collaboration, O. ReimerFermi LAT collaboration, F. RydeFermi LAT collaboration, M. Sánchez-CondeFermi LAT collaboration, P. M. Saz ParkinsonFermi LAT collaboration, D. SeriniFermi LAT collaboration, C. SgròFermi LAT collaboration, V. SharmaFermi LAT collaboration, E. J. SiskindFermi LAT collaboration, G. SpandreFermi LAT collaboration, P. SpinelliFermi LAT collaboration, D. J. SusonFermi LAT collaboration, H. TajimaFermi LAT collaboration, D. TakFermi LAT collaboration, J. B. ThayerFermi LAT collaboration, D. F. TorresFermi LAT collaboration, J. ValverdeFermi LAT collaboration, G. ZaharijasFermi LAT collaboration, S. LesageFermi GBM collaboration, M. S. BriggsFermi GBM collaboration, E. BurnsFermi GBM collaboration, S. BalaFermi GBM collaboration, P. N. BhatFermi GBM collaboration, W. H. ClevelandFermi GBM collaboration, S. DalessiFermi GBM collaboration, C. de BarraFermi GBM collaboration, M. GibbyFermi GBM collaboration, M. M. GilesFermi GBM collaboration, R. HamburgFermi GBM collaboration, B. A. HristovFermi GBM collaboration, C. M. HuiFermi GBM collaboration, D. KocevskiFermi GBM collaboration, B. MailyanFermi GBM collaboration, C. MalacariaFermi GBM collaboration, S. McBreenFermi GBM collaboration, S. PoolakkilFermi GBM collaboration, O. J. RobertsFermi GBM collaboration, L. ScottonFermi GBM collaboration, P. VeresFermi GBM collaboration, A. von KienlinFermi GBM collaboration, C. A. Wilson-HodgeFermi GBM collaboration, J. WoodFermi GBM collaboration","doi":"arxiv-2409.04580","DOIUrl":"https://doi.org/arxiv-2409.04580","url":null,"abstract":"We present a complete analysis of Fermi Large Area Telescope (LAT) data of\u0000GRB 221009A, the brightest Gamma-Ray Burst (GRB) ever detected. The burst\u0000emission above 30 MeV detected by the LAT preceded by 1 s the low-energy (< 10\u0000MeV) pulse that triggered the Fermi Gamma-Ray Burst Monitor (GBM), as has been\u0000observed in other GRBs. The prompt phase of GRB 221009A lasted a few hundred\u0000seconds. It was so bright that we identify a Bad Time Interval (BTI) of 64\u0000seconds caused by the extremely high flux of hard X-rays and soft gamma rays,\u0000during which the event reconstruction efficiency was poor and the dead time\u0000fraction quite high. The late-time emission decayed as a power law, but the\u0000extrapolation of the late-time emission during the first 450 seconds suggests\u0000that the afterglow started during the prompt emission. We also found that\u0000high-energy events observed by the LAT are incompatible with synchrotron\u0000origin, and, during the prompt emission, are more likely related to an extra\u0000component identified as synchrotron self-Compton (SSC). A remarkable 400 GeV\u0000photon, detected by the LAT 33 ks after the GBM trigger and directionally\u0000consistent with the location of GRB 221009A, is hard to explain as a product of\u0000SSC or TeV electromagnetic cascades, and the process responsible for its origin\u0000is uncertain. Because of its proximity and energetic nature, GRB 221009A is an\u0000extremely rare event.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-lensing flares from black hole binaries IV: the number of detectable shadows","authors":"Kevin Park, Chengcheng Xin, Jordy Davelaar, Zoltan Haiman","doi":"arxiv-2409.04583","DOIUrl":"https://doi.org/arxiv-2409.04583","url":null,"abstract":"Sub-parsec supermassive black hole (SMBH) binaries are expected to be common\u0000in active galactic nuclei (AGN), as a result of the hierarchical build-up of\u0000galaxies via mergers. While direct evidence for these compact binaries is\u0000lacking, a few hundred candidates have been identified, most based on the\u0000apparent periodicities of their optical light-curves. Since these signatures\u0000can be mimicked by AGN red-noise, additional evidence is needed to confirm\u0000their binary nature. Recurring self-lensing flares (SLF), occurring whenever\u0000the two BHs are aligned with the line of sight within their Einstein radii,\u0000have been suggested as additional binary signatures. Furthermore, in many\u0000cases, lensing flares are also predicted to contain a \"dip\", whenever the\u0000lensed SMBH's shadow is comparable in angular size to the binary's Einstein\u0000radius. This feature would unambiguously confirm binaries and additionally\u0000identify SMBH shadows that are spatially unresolvable by high-resolution VLBI.\u0000Here we estimate the number of quasars for which these dips may be detectable\u0000by LSST, by extrapolating the quasar luminosity function to faint magnitudes,\u0000and assuming that SMBH binaries are randomly oriented and have mass-ratios\u0000following those in the Illustris simulations. Under plausible assumptions about\u0000quasar lifetimes, binary fractions, and Eddington ratios, we expect tens of\u0000thousands of detectable flares, of which several dozen contain measurable dips.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ZTF SN Ia DR2: Overview","authors":"Mickael Rigault, Mathew Smith, Ariel Goobar, Kate Maguire, Georgios Dimitriadis, Umut Burgaz, Suhail Dhawan, Jesper Sollerman, Nicolas Regnault, Marek Kowalski, Melissa Amenouche, Marie Aubert, Chloé Barjou-Delayre, Julian Bautista, Josh S. Bloom, Bastien Carreres, Tracy X. Chen, Yannick Copin, Maxime Deckers, Dominique Fouchez, Christoffer Fremling, Lluis Galbany, Madeleine Ginolin, Matthew Graham, Mancy M. Kasliwal, W. D'Arcy Kenworthy, Young-Lo Kim, Dylan Kuhn, Frank F. Masci, Tomas Müller-Bravo, Adam Miller, Joel Johansson, Jakob Nordin, Peter Nugent, Igor Andreoni, Eric Bellm, Marc Betoule, Mahmoud Osman, Dan Perley, Brodie Popovic, Philippe Rosnet, Damiano Rosselli, Florian Ruppin, Robert Senzel, Ben Rusholme, Tassilo Schweyer, Jacco H. Terwel, Alice Townsend, Andy Tzanidakis, Avery Wold, Josiah Purdum, Yu-Jing Qin, Benjamin Racine, Simeon Reusch, Reed Riddle, Lin Yan","doi":"arxiv-2409.04346","DOIUrl":"https://doi.org/arxiv-2409.04346","url":null,"abstract":"We present the first homogeneous release of several thousand Type Ia\u0000supernovae (SNe Ia), all having spectroscopic classification, and spectroscopic\u0000redshifts for half the sample. This release, named the \"DR2\", contains 3628\u0000nearby (z < 0.3) SNe Ia discovered, followed and classified by the Zwicky\u0000Transient Facility survey between March 2018 and December 2020. Of these, 3000\u0000have good-to-excellent sampling and 2667 pass standard cosmology light-curve\u0000quality cuts. This release is thus the largest SN Ia release to date,\u0000increasing by an order of magnitude the number of well characterized\u0000low-redshift objects. With the \"DR2\", we also provide a volume-limited (z <\u00000.06) sample of nearly a thousand SNe Ia. With such a large, homogeneous and\u0000well controlled dataset, we are studying key current questions on SN cosmology,\u0000such as the linearity SNe Ia standardization, the SN and host dependencies, the\u0000diversity of the SN Ia population, and the accuracy of the current light-curve\u0000modeling. These, and more, are studied in detail in a series of articles\u0000associated with this release. Alongside the SN Ia parameters, we publish our\u0000force-photometry gri-band light curves, 5138 spectra, local and global host\u0000properties, observing logs, and a python tool to ease use and access of these\u0000data. The photometric accuracy of the \"DR2\" is not yet suited for cosmological\u0000parameter inference, which will follow as \"DR2.5\" release. We nonetheless\u0000demonstrate that the multi-thousand SN Ia Hubble Diagram has a typical 0.15 mag\u0000scatter.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymptotic-state prediction for fast flavor transformation in neutron star mergers","authors":"Sherwood Richers, Julien Froustey, Somdutta Ghosh, Francois Foucart, Javier Gomez","doi":"arxiv-2409.04405","DOIUrl":"https://doi.org/arxiv-2409.04405","url":null,"abstract":"Neutrino flavor instabilities appear to be omnipresent in dense astrophysical\u0000environments, thus presenting a challenge to large-scale simulations of\u0000core-collapse supernovae and neutron star mergers (NSMs). Subgrid models offer\u0000a path forward, but require an accurate determination of the local outcome of\u0000such conversion phenomena. Focusing on \"fast\" instabilities, related to the\u0000existence of a crossing between neutrino and antineutrino angular\u0000distributions, we consider a range of analytical mixing schemes, including a\u0000new, fully three-dimensional one, and also introduce a new machine learning\u0000(ML) model. We compare the accuracy of these models with the results of several\u0000thousands of local dynamical calculations of neutrino evolution from the\u0000conditions extracted from classical NSM simulations. Our ML model shows good\u0000overall performance, but struggles to generalize to conditions from a NSM\u0000simulation not used for training. The multidimensional analytic model performs\u0000and generalizes even better, while other analytic models (which assume\u0000axisymmetric neutrino distributions) do not have reliably high performances, as\u0000they notably fail as expected to account for effects resulting from strong\u0000anisotropies. The ML and analytic subgrid models extensively tested here are\u0000both promising, with different computational requirements and sources of\u0000systematic errors.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Triple trouble with PSR J1618-3921: Mass measurements and orbital dynamics of an eccentric millisecond pulsar","authors":"K. Grunthal, V. Venkatraman Krishnan, P. C. C. Freire, M. Kramer, M. Bailes, S. Buchner, M. Burgay, A. D. Cameron, C. -H. R. Chen, I. Cognard, L. Guillemot, M. E. Lower, A. Possenti, G. Theureau","doi":"arxiv-2409.03615","DOIUrl":"https://doi.org/arxiv-2409.03615","url":null,"abstract":"PSR J1618-3921 is one of five known millisecond pulsars (MSPs) in eccentric\u0000orbits (eMPSs) located in the Galactic plane, whose formation is poorly\u0000understood. Earlier studies of these objects revealed significant discrepancies\u0000between observation and predictions from standard binary evolution scenarios of\u0000pulsar-Helium white dwarf binaries. We conducted observations with the L-band\u0000receiver of the MeerKAT radio telescope and the UWL receiver of the Parkes\u0000Murriyang radio telescope between 2019 and 2021. These data were added to\u0000archival observations. We perform an analysis of this joint 23-year-dataset. We\u0000use the recent observations to give a brief account of the emission properties\u0000of J1618-3921, including a Rotating Vector model fit of the linear polarisation\u0000position angle of the pulsar. The long timing baseline allowed for a highly\u0000significant measurement of the rate of advance of periastron of $dot{omega}$.\u0000We can only report a low significance detection of the orthometric Shapiro\u0000delay parameters $h_3$ and $varsigma$, leading to mass estimates of the total\u0000and individual binary masses. We detect an unexpected change in the orbital\u0000period of, which is an order of magnitude larger and carries an opposite sign\u0000to what is expected from Galactic acceleration and the Shklovskii effect. We\u0000also detect a significant second derivative of the spin frequency. Furthermore,\u0000we report an unexpected, abrupt change of the mean pulse profile in June 2021\u0000with unknown origin. We propose that the anomalous $dot{P_b}$ and $ddot{f}$\u0000indicate an additional varying acceleration due to a nearby mass, i.e., the\u0000J1618-3921 binary system is likely part of a hierarchical triple. This finding\u0000suggests that at least some eMSPs might have formed in triple star systems.\u0000Although the uncertainties are large, the binary companion mass is consistent\u0000with the $P_b$ - $M_{WD}$ relation.","PeriodicalId":501343,"journal":{"name":"arXiv - PHYS - High Energy Astrophysical Phenomena","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142206585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}