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JWST UNCOVER: Discovery of z > 9 Galaxy Candidates Behind the Lensing Cluster Abell 2744

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arXiv 2023年

作者： Atek, Hakim Chemerynska, Iryna Wang, Bingjie Furtak, Lukas Weibel, Andrea Oesch, Pascal Weaver, John R. Labbé, Ivo Bezanson, Rachel van Dokkum, Pieter Zitrin, Adi Dayal, Pratika Williams, Christina C. Nannayakkara, Themiya Price, Sedona H. Brammer, Gabriel Goulding, Andy D. Leja, Joel Marchesini, Danilo Nelson, Erica J. Pan, Richard Whitaker, Katherine E. Institut d'Astrophysique de Paris CNRS Sorbonne Université 98bis Boulevard Arago Paris75014 France Department of Astronomy & Astrophysics The Pennsylvania State University University ParkPA16802 United States Institute for Computational & Data Sciences The Pennsylvania State University University ParkPA16802 United States Institute for Gravitation and the Cosmos The Pennsylvania State University University ParkPA16802 United States Physics Department Ben-Gurion University of the Negev P.O. Box 653 Be'er-Sheva84105 Israel Department of Astronomy University of Geneva Chemin Pegasi 51 Versoix1290 Switzerland Department of Astronomy University of Massachusetts AmherstMA01003 United States Centre for Astrophysics and Supercomputing Swinburne University of Technology MelbourneVIC3122 Australia Department of Physics and Astronomy PITT PACC University of Pittsburgh PittsburghPA15260 United States Department of Astronomy Yale University New HavenCT06511 United States Kapteyn Astronomical Institute University of Groningen P.O. Box 800 Groningen9700 AV Netherlands NSF's National Optical-Infrared Astronomy Research Laboratory 950 N. Cherry Avenue TucsonAZ85719 United States Niels Bohr Institute University of Copenhagen Jagtvej 128 København NDK-2200 Denmark Department of Astrophysical Sciences Princeton University PrincetonNJ08544 United States Department of Physics and Astronomy Tufts University 574 Boston Ave. MedfordMA02155 United States Department for Astrophysical and Planetary Science University of Colorado BoulderCO80309 United States

We present the results of a search for high-redshift (z > 9) galaxy candidates in the JWST UNCOVER survey, using deep NIRCam and NIRISS imaging in 7 bands over ∼ 45 arcmin2 and ancillary HST observations. The NIRCam observations reach a 5 − σ limiting magnitude of ∼ 29.2 AB. The identification of high−z candidates relies on a combination of a dropout selection and photometric redshifts. We find 16 candidates at 9 ★/M☉) ☉ yr−1), confirming previous findings in early JWST observations of z > 9. A few galaxies at z ∼ 9 − 10 appear to show a clear Balmer break between the F356W and F444W/F410M bands, which helps constrain their stellar mass. We estimate blue UV continuum slopes between β = −1.8 and −2.3, typical for early galaxies at z > 9 but not as extreme as the bluest recently discovered sources. We also find evidence for a rapid redshift-evolution of the mass-luminosity relation and a redshift-evolution of the UV continuum slope for a given range of intrinsic magnitude, in line with theoretical predictions. These findings suggest that deeper JWST observations are needed to reach the fainter galaxy population at those early epochs, and follow-up spectroscopy will help better constrain the physical properties and star formation histories of a larger sample of galaxies. © 2023, CC BY.

关键词： Stars

PANDORA project: photo-nuclear reactions below A=60

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arXiv 2022年

作者： Tamii, A. Pellegri, L. Söderström, P.-A. Allard, D. Goriely, S. Inakura, T. Khan, E. Kido, E. Kimura, M. Litvinova, E. Nagataki, S. von Neumann-Cosel, P. Pietralla, N. Shimizu, N. Tsoneva, N. Utsuno, Y. Adachi, S. Bahini, A. Balabanski, D. Baret, B. Bekker, J.A.C. Binda, S.D. Boicu, E. Bracco, A. Brandherm, I. Brezeanu, M. Brummer, J.W. Camera, F. Crespi, F.C.L. Dalal, R. Donaldson, L.M. Fujikawa, Y. Furuno, T. Haoning, H. Honda, Y. Gavrilescu, A. Inoue, A. Isaak, J. Jivan, H. Jones, P.M. Jongile, S. Kawabata, T. Khumalo, T. Kiener, J. Kleemann, J. Kobayashi, N. Koshio, Y. Kuşoğlu, A. Li, K.C.W. Malatji, K.L. Molaeng, R.E. Motoki, H. Murata, M. Netshiya, A. Neveling, R. Niina, R. Oliver, J. Okamoto, S. Ota, S. Papst, O. Parizot, E. Petruse, T. Reen, M.S. Ring, P. Sakanashi, K. Sideras-Haddad, E. Siem, S. Spall, M. Suda, T. Sudo, T. Taniguchi, Y. Tatischeff, V. Utsunomiya, H. Wang, H. Werner, V. Wibowo, H. Wiedeking, M. Wieland, O. Xu, Y. Osaka University Ibaraki567-0047 Japan School of Physics University of the Witwatersrand Johannesburg2050 South Africa iThemba Laboratory for Accelerator Based Sciences Somerset West7129 South Africa Str. Reactorului 30 Bucharest-Măgurele077125 Romania Laboratoire Astroparticule et Cosmologie Université Paris Cité CNRS ParisF-75013 France Institut d’Astronomie et d’Astrophysique Université Libre de Bruxelles Campus de la Plaine CP 226 Brussels1050 Belgium Tokyo Institute of Technology 2-12-1 Ookayama Meguro Tokyo152-8550 Japan IJCLab Université Paris-Saclay CNRS IN2P3 Orsay Cedex91405 France RIKEN 2-1 Hirosawa Saitama Wako351-0198 Japan Department of Physics Hokkaido University Sapporo060-0810 Japan Nuclear Reaction Data Centre Faculty of Science Hokkaido University Sapporo060-0810 Japan Department of Physics Western Michigan University KalamazooMI49008 United States Institut für Kernphysik Technische Universität Darmstadt Darmstadt64289 Germany Center for Computational Sciences University of Tsukuba Tsukuba305-8577 Japan Advanced Science Research Center Japan Atomic Energy Agency Ibaraki Tokai319-1195 Japan Cyclotron and Radioisotope Center Tohoku University 6-3 Aoba Aramaki Aoba Miyagi Sendai980-8578 Japan University of Bucharest Atomistilor 405 Bucharest-Măgurele077125 Romania Dipartimento di Fisica dell’Università degli Studi di Milano MilanoI-20133 Italy INFN Sezione di Milano MilanoI-20133 Italy Guru Jambheshwar University of Science and Technology Hisar125001 India Department of Physics Kyoto University Kitashirakawa Oiwake-Cho Kyoto606-8502 Japan Department of Physics Osaka University Toyonaka Osaka560-0043 Japan Politehnica University of Bucharest Bucharest Romania Department of Physics Faculty of Science Istanbul University Vezneciler/ Istanbul Fatih34134 Turkey Department of Physics University of Oslo P.O. Box 1048 Blindern OsloN-0316 Norway Department of Physics Akal University Punjab

Photo-nuclear reactions of light nuclei below a mass of A = 60 are studied experimentally and theoretically by the PANDORA (Photo-Absorption of Nuclei and Decay Observation for Reactions in Astrophysics) project. Two experimental methods, virtual-photon excitation by proton scattering and real-photo absorption by a high-brilliance gamma-ray beam produced by laser Compton scattering, will be applied to measure the photo-absorption cross sections and the decay branching ratio of each decay channel as a function of the photon energy. Several nuclear models, e.g. anti-symmetrized molecular dynamics, mean-field type models, a large-scale shell model, and ab initio models, will be employed to predict the photo-nuclear reactions. The uncertainty in the model predictions will be evaluated from the discrepancies between the model predictions and the experimental data. The data and the predictions will be implemented in a general reaction calculation code TALYS. The results will be applied to the simulation of the photo-disintegration process of ultra-high-energy cosmic rays in inter-galactic propagation. © 2022, CC BY-NC-ND.

关键词： Gamma rays

DUALZ - Deep UNCOVER-ALMA Legacy High-Z Survey

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arXiv 2023年

作者： Fujimoto, Seiji Bezanson, Rachel Labbe, Ivo Brammer, Gabriel Price, Sedona H. Wang, Bingjie Weaver, John R. Fudamoto, Yoshinobu Oesch, Pascal A. Williams, Christina C. Dayal, Pratika Feldmann, Robert Greene, Jenny E. Leja, Joel Whitaker, Katherine E. Zitrin, Adi Cutler, Sam E. Furtak, Lukas J. Pan, Richard Chemerynska, Iryna Kokorev, Vasily Miller, Tim B. Atek, Hakim Van Dokkum, Pieter Juneau, Stéphanie Kassin, Susan Khullar, Gourav Marchesini, Danilo Maseda, Michael Nelson, Erica J. Setton, David J. Smit, Renske Department of Astronomy The University of Texas at Austin AustinTX78712 United States Department of Physics and Astronomy Pitt Pacc University of Pittsburgh PittsburghPA15260 United States Centre for Astrophysics and Supercomputing Swinburne University of Technology MelbourneVIC3122 Australia Niels Bohr Institute University of Copenhagen Jagtvej 128 Kobenhavn N DK-2200 Denmark Department of Astronomy & Astrophysics The Pennsylvania State University University ParkPA16802 United States Institute for Computational & Data Sciences The Pennsylvania State University University ParkPA16802 United States Institute for Gravitation and the Cosmos The Pennsylvania State University University ParkPA16802 United States Department of Astronomy University of Massachusetts AmherstMA01003 United States Waseda Research Institute for Science and Engineering Faculty of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku Tokyo169-8555 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Tokyo Mitaka Japan Department of Astronomy University of Geneva Chemin Pegasi 51 Versoix1290 Switzerland NSF's National Optical-Infrared Astronomy Research Laboratory 950 N. Cherry Avenue TucsonAZ85719 United States Steward Observatory University of Arizona 933 North Cherry Avenue TucsonAZ85721 United States Kapteyn Astronomical Institute University of Groningen Groningen9700 AV Netherlands Institute for Computational Science University of Zurich ZurichCH-8057 Switzerland Department of Astrophysical Sciences Princeton University 4 Ivy Lane PrincetonNJ08544 United States Physics Department Ben-Gurion University of the Negev P.O. Box 653 Beér-Sheva 84105 Israel Department of Physics and Astronomy Tufts University 574 Boston Ave. MedfordMA02155 United States Institut d'Astrophysique de Paris Cnrs Sorbonne Université 98bis Boulevard Arago Paris75014 France Department of Astronomy Yale University New HavenCT06511 United States D

We present the survey design and initial results of the ALMA Cycle 9 program of DUALZ, which aims to establish a joint ALMA and JWST public legacy field targeting the massive galaxy cluster Abell 2744. DUALZ features a contiguous 4′×6′ ALMA 30-GHz-wide mosaic in Band 6, covering areas of μ > 2 down to a sensitivity of σ = 32.7 μJy. Through a blind search, we identified 69 dust continuum sources at S/N 5.0 with median redshift and intrinsic 1.2-mm flux of z = 2.30 and S1.2mmint = 0.24 mJy. Of these, 27 have been spectroscopically confirmed, leveraged by the latest NIRSpec observations, while photometric redshifts are also constrained by the comprehensive HST, NIRCam, and ALMA data sets for the remaining sources. With priors, we further identify a [C ii]158 μm line emitter at z = 6.3254 ± 0.0004, confirmed by the latest NIRSpec spectroscopy. The NIRCam counterparts of the 1.2-mm continuum exhibit undisturbed morphologies, denoted either by disk or spheroid, implying the triggers for the faint mm emission are less catastrophic than mergers. We have identified 8 HST-dark galaxies (F150W>27 mag, F150W-F444W>2.3) and 2 JWST-dark (F444W>30 mag) galaxy candidates among the ALMA continuum sources. The former includes face-on disk galaxies, hinting that substantial dust obscuration does not always result from inclination. We also detect a marginal dust emission from an X-ray-detected galaxy at zspec = 10.07, suggesting an active co-evolution of the central black hole and its host. We assess the infrared luminosity function up to z ∼ 10 and find it consistent with predictions from galaxy formation models. To foster diverse scientific outcomes from the community, we publicly release reduced ALMA mosaic maps, cubes, and the source cataloga) © 2023, CC BY.

关键词： Galaxies

The Low-Redshift Lyman Continuum Survey: The Roles of Stellar Feedback and ISM Geometry in LyC Escape

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arXiv 2024年

作者： Flury, Sophia R. Jaskot, Anne E. Saldana-Lopez, Alberto Oey, M.S. Chisholm, John Amorín, Ricardo Bait, Omkar Borthakur, Sanchayeeta Carr, Cody Ferguson, Henry C. Giavalisco, Mauro Hayes, Matthew Heckman, Timothy Henry, Alaina Ji, Zhiyuan Komarova, Lena Leclercq, Floriane Reste, Alexandra Le McCandliss, Stephan Marques-Chaves, Rui Östlin, Göran Pentericci, Laura Ravindranath, Swara Rutkowski, Michael Scarlata, Claudia Schaerer, Daniel Thuan, Trinh Trebitsch, Maxime Vanzella, Eros Verhamme, Anne Wang, Bingjie Worseck, Gábor Xu, Xinfeng Department of Astronomy University of Massachusetts Amherst AmherstMA01002 United States Institute for Astronomy University of Edinburgh Royal Observatory EdinburghEH9 3HJ United Kingdom Department of Astronomy Williams College WilliamstownMA01267 United States Department of Astronomy Oskar Klein Centre Stockholm University Stockholm106 91 Sweden University of Michigan Department of Astronomy 323 West Hall 1085 S. University Ave Ann ArborMI48109 United States Department of Astronomy The University of Texas at Austin 2515 Speedway Stop C1400 AustinTX78712-1205 United States Unidad Asociada al CSIC Plaza San Juan 1 Teruel44001 Spain Departamento de Astronomía Universidad de La Serena Avda. Juan Cisternas 1200 La Serena Chile SKA Observatory Jodrell Bank Lower Withington MacclesfieldSK11 9FT United Kingdom School of Earth and Space Exploration Arizona State University 781 Terrace Mall TempeAZ85287 United States Center for Cosmology and Computational Astrophysics Institute for Advanced Study in Physics Zhejiang University Hangzhou310058 China Institute of Astronomy School of Physics Zhejiang University Hangzhou310058 China Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Center for Astrophysical Sciences Department of Physics & Astronomy Johns Hopkins University BaltimoreMD21218 United States Center for Astrophysical Sciences Department of Physics & Astronomy Johns Hopkins University BaltimoreMD21218 United States Steward Observatory University of Arizona 933 N. Cherry Avenue TucsonAZ85721 United States Minnesota Institute for Astrophysics University of Minnesota MinneapolisMN55455 United States Department of Astronomy University of Geneva 51 Chemin Pegasi Versoix1290 Switzerland INAF-Osservatorio Astronomico di Roma Via di Frascati 33 Monte Porzio Catone00078 Italy Astrophysics Science Division NASA Goddard Space Flight Center 8800 Greenbelt Road GreenbeltMD20771 United St

One of the fundamental questions of cosmology is the origin and mechanism(s) responsible for the reionization of the Universe beyond z ∼ 6. To address this question, many studies over the past decade have focused on local (z ∼ 0.3) galaxies which leak ionizing radiation (Lyman continuum or LyC). However, line-of-sight effects and data quality have prohibited deeper insight into the nature of LyC escape. To circumvent these limitations, we analyze stacks of a consolidated sample of HST/COS observations of the LyC in 89 galaxies at z ∼ 0.3. From fitting of the continuum, we obtain information about the underlying stellar populations and neutral ISM geometry. We find that most LyC nondetections are not leaking appreciable LyC (fLyC esc 5%) also requires a confluence of young stars and ionizing feedback. A two-stage burst of star formation is critical to producing this optimal LyC escape scenario and should be considered fundamental to identifying LyC emitters at the epoch of reionization. © 2024, CC BY-NC-ND.

关键词： Supernovae

Gaia-4b and 5b: Radial Velocity Confirmation of Gaia Astrometric Orbital Solutions Reveal a Massive Planet and a Brown Dwarf Orbiting Low-mass Stars

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arXiv 2024年

作者： Stefánsson, Guðmundur Mahadevan, Suvrath Winn, Joshua N. Marcussen, Marcus L. Kanodia, Shubham Albrecht, Simon Fitzmaurice, Evan Mikulskitye, Onė Cañas, Caleb I. Espinoza-Retamal, Juan Ignacio Zwart, Yiri Krolikowski, Daniel M. Hotnisky, Andrew Robertson, Paul Alvarado-Montes, Jaime A. Bender, Chad F. Blake, Cullen H. Callingham, Joe R. Cochran, William D. Delamer, Megan Diddams, Scott A. Dong, Jiayin Fernandes, Rachel B. Giovanazzi, Mark R. Halverson, Samuel Libby-Roberts, Jessica Logsdon, Sarah E. McElwain, Michael W. Ninan, Joe P. Rajagopal, Jayadev Reji, Varghese Roy, Arpita Schwab, Christian Wright, Jason T. Anton Pannekoek Institute for Astronomy University of Amsterdam Science Park 904 Amsterdam1098 XH Netherlands Department of Astronomy & Astrophysics 525 Davey Laboratory The Pennsylvania State University University ParkPA16802 United States Astrobiology Research Center 525 Davey Laboratory The Pennsylvania State University University ParkPA16802 United States Center for Exoplanets and Habitable Worlds 525 Davey Laboratory The Pennsylvania State University University ParkPA16802 United States Department of Astrophysical Sciences Princeton University 4 Ivy Lane PrincetonNJ08540 United States Stellar Astrophysics Centre Department of Physics and Astronomy Aarhus University Ny Munkegade 120 Aarhus C8000 Denmark Earth and Planets Laboratory Carnegie Institution for Science 5241 Broad Branch Road NW WashingtonDC20015 United States Institute for Computational and Data Sciences The Pennsylvania State University University ParkPA16802 United States NASA Goddard Space Flight Center 8800 Greenbelt Road GreenbeltMD20771 United States Instituto de Astrofísica Pontificia Universidad Católica de Chile Av. Vicuña Mackenna 4860 Macul Santiago782-0436 Chile Millennium Institute for Astrophysics Santiago Chile Steward Observatory The University of Arizona 933 N. Cherry Ave TucsonAZ85721 United States Department of Physics & Astronomy The University of California Irvine IrvineCA92697 United States School of Mathematical and Physical Sciences Macquarie University Balaclava Road North RydeNSW2109 Australia The Macquarie University Astrophysics and Space Technologies Research Centre Macquarie University Balaclava Road North RydeNSW2109 Australia Department of Physics and Astronomy University of Pennsylvania 209 S 33rd St PhiladelphiaPA19104 United States Leiden Observatory Leiden University PO Box 9513 Leiden2300 RA Netherlands ASTRON Netherlands Institute for Radio Astronomy Oude Hoogeveensedijk 4 Dwingeloo7991 PD Netherlands McDonald O

Gaia astrometry of nearby stars is precise enough to detect the tiny displacements induced by substellar companions, but radial velocity data are needed for definitive confirmation. Here we present radial velocity follow-up observations of 28 M and K stars with candidate astrometric substellar companions, which led to the confirmation of two systems, Gaia-4b and Gaia-5b, and the refutation of 21 systems as stellar binaries. Gaia-4b is a massive planet (M = 11.8 ± 0.7 MJ) in a P = 571.3 ± 1.4 day orbit with a projected semi-major axis a0 = 0.312 ±0.040 mas orbiting a 0.644 ±0.02 M☉ star. Gaia-5b is a brown dwarf (M = 20.9 ± 0.5 MJ) in a P = 358.58 ± 0.19 days eccentric e = 0.6412 ± 0.0027 orbit with a projected angular semi-major axis of a0 = 0.947 ± 0.038 mas around a 0.34 ± 0.03M☉ star. Gaia-4b is one of the first exoplanets discovered via the astrometric technique, and is one of the most massive planets known to orbit a low-mass star. Copyright © 2024, The Authors. All rights reserved.

关键词： Orbits

Neuroscience needs Network Science

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arXiv 2023年

作者： Barabási, Dániel L. Bianconi, Ginestra Bullmore, Ed Burgess, Mark Chung, SueYeon Eliassi-Rad, Tina George, Dileep Kovács, István A. Makse, Hernán Papadimitriou, Christos Nichols, Thomas E. Sporns, Olaf Stachenfeld, Kim Toroczkai, Zoltán Towlson, Emma K. Zador, Anthony M. Zeng, Hongkui Barabási, Albert-László Bernard, Amy Buzsáki, György Biophysics Program Harvard University CambridgeMA United States Department of Molecular and Cellular Biology Center for Brain Science Harvard University CambridgeMA United States School of Mathematical Sciences Queen Mary University of London LondonE1 4NS United Kingdom The Alan Turing Institute The British Library LondonNW1 2DB United Kingdom Department of Psychiatry Wolfson Brain Imaging Centre University of Cambridge Cambridge United Kingdom ChiTek-i AS Oslo Norway Center for Neural Science New York University New YorkNY United States Center for Computational Neuroscience Flatiron Institute Simons Foundation New YorkNY United States Network Science Institute Northeastern University BostonMA United States Khoury College of Computer Sciences Northeastern University BostonMA United States Santa Fe Institute Santa FeNM United States DeepMind United Kingdom Department of Physics and Astronomy Northwestern University 633 Clark Street EvanstonIL60208 United States Northwestern Institute on Complex Systems Chambers Hall Northwestern University 600 Foster St EvanstonIL60208 United States Levich Institute and Physics Department City College of New York New YorkNY10031 United States Columbia University New YorkNY10027 United States Big Data Institute Li Ka Shing Centre for Health Information and Discovery Nuffield Department of Population Health University of Oxford OxfordOX3 7LF United Kingdom Wellcome Centre for Integrative Neuroimaging FMRIB Nuffield Department of Clinical Neurosciences University of Oxford OxfordOX3 9DU United Kingdom Department of Psychological and Brain Sciences Indiana University BloomingtonIN47405 United States Department of Physics University of Notre Dame 225 Nieuwland Science Hall Notre DameIN46556 United States Department of Computer Science Department of Physics and Astronomy Hotchkiss Brain Institute Children’s Research Hospital University of Calgary CalgaryAB Canada Cold Spring Harbor Laboratory

The brain is a complex system comprising a myriad of interacting elements, posing significant challenges in understanding its structure, function, and dynamics. Network science has emerged as a powerful tool for studying such intricate systems, offering a framework for integrating multiscale data and complexity. Here, we discuss the application of network science in the study of the brain, addressing topics such as network models and metrics, the connectome, and the role of dynamics in neural networks. We explore the challenges and opportunities in integrating multiple data streams for understanding the neural transitions from development to healthy function to disease, and discuss the potential for collaboration between network science and neuroscience communities. We underscore the importance of fostering interdisciplinary opportunities through funding initiatives, workshops, and conferences, as well as supporting students and postdoctoral fellows with interests in both disciplines. By uniting the network science and neuroscience communities, we can develop novel network-based methods tailored to neural circuits, paving the way towards a deeper understanding of the brain and its functions. © 2023, CC BY-NC-SA.

关键词： Complex networks

Neutron star radius-to-mass ratio from partial accretion disc occultation as measured through Fe Kα line profiles

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arXiv 2020年

作者： la Placa, Riccardo Stella, Luigi Papitto, Alessandro Bakala, Pavel Di Salvo, Tiziana Falanga, Maurizio de Falco, Vittorio de Rosa, Alessandra Department of Physics G. Marconi University of Rome "La Sapienza" Italy Italy Research Centre for Computational Physics and Data Processing Silesian University in Opava Czech Republic M. R. Štefánik Observatory and Planetarium Hlohovec Slovakia Università degli Studi di Palermo Dipartimento di Fisica e Chimica Palermo Italy Bern Switzerland International Space Science Institute Beijing China INAF/Istituto di Astrofisica e Planetologia Spaziali Roma Italy

We present a new method to measure the radius-to-mass ratio (R/M) of weakly magnetic, disc-accreting neutron stars by exploiting the occultation of parts of the inner disc by the star itself. This occultation imprints characteristic features on the X-ray line profile that are unique and are expected to be present in low mass X-ray binary systems seen under inclinations higher than ~65 degrees. We analyse a NuSTAR observation of a good candidate system, 4U 1636-53, and find that X-ray spectra from current instrumentation are unlikely to single out the occultation features owing to insufficient signal-to-noise. Based on an extensive set of simulations we show that large-area X-ray detectors of the future generation could measure R/M to ~2 ÷ 3% precision over a range of inclinations. Such is the precision in radius determination required to derive tight constraints on the equation of state of ultradense matter and it represents the goal that other methods too aim to achieve in the future. Copyright © 2020, The Authors. All rights reserved.

关键词： Stars

Mass of the active galactic nucleus black hole XMMUJ134736.6+173403

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arXiv 2019年

作者： Goluchová, K. Török, G. Šrámková, E. Abramowicz, Marek A. Stuchlík, Z. Horák, Jiří Institute of Physics Research Centre for Computational Physics and Data Processing Research Centre for Theoretical Physics and Astrophysics Faculty of Philosophy & Science Silesian University in Opava Bezručovo nám. 13 OpavaCZ-746 01 Czech Republic Astronomical Institute Boční II 1401/2a Praha 4-SpořilovCZ-14131 Czech Republic

A recent study of the X-ray source XMMUJ134736.6+173403 has revealed a strong quasi-periodic modulation of the X-ray flux. The observation of two quasiperiodic oscillations (QPOs) that occur on a daily timescale and exhibit a 3:1 frequency ratio strongly supports the evidence for the presence of an active galactic nucleus black hole (AGN BH). Assuming an orbital origin of QPOs, we calculated the upper and lower limit on AGN BH mass M and found M ≈ 107 − 109 Mo. When we compare this to mass estimates of other sources, XMMUJ134736.6+173403 appears to be the most massive source with commensurable QPO frequencies, and its mass represents the current observational upper limit on AGN BH mass based on QPO observations. We note that it will be crucial for the falsification of particular resonance models of QPOs whether only a single QPO with a frequency that completes the harmonic sequence 3: 2: 1 is found in this source, or if a new different pair of QPOs with frequencies in the 3: 2 ratio is found. The former case would agree with the prediction of the 3: 2 epicyclic resonance model and BH mass M ≈ (5a2 + 8a + 8) × 107 Mo, where a is a dimensionless BH spin. Copyright © 2019, The Authors. All rights reserved.

关键词： Stars

SN2023ixf in Messier 101: A Variable Red Supergiant as the Progenitor Candidate to a Type II Supernova

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arXiv 2023年

作者： Kilpatrick, Charles D. Foley, Ryan J. Jacobson-Galán, Wynn V. Piro, Anthony L. Smartt, Stephen J. Drout, Maria R. Gagliano, Alexander Gall, Christa Hjorth, Jens Jones, David O. Mandel, Kaisey S. Margutti, Raffaella Ramirez-Ruiz, Enrico Ransome, Conor L. Villar, V. Ashley Coulter, David A. Gao, Hua Matthews, David Jacob Taggart, Kirsty Zenati, Yossef Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States Department of Astronomy and Astrophysics University of California Santa CruzCA95064 United States Department of Astronomy and Astrophysics University of California BerkeleyCA94720 United States The Observatories of the Carnegie Institution for Science 813 Santa Barbara St. PasadenaCA91101 United States Astrophysics Research Centre School of Mathematics and Physics Queen's University Belfast BelfastBT7 1NN United Kingdom Department of Physics University of Oxford Denys Wilkinson Building Keble Road OxfordOX1 3RH United Kingdom David A. Dunlap Department of Astronomy and Astrophysics University of Toronto 50 St. George Street TorontoONM5S 3H4 Canada Department of Astronomy University of Illinois 1002 W. Green St. Urbana-ChampaignIL61801 United States Center for Astrophysical Surveys National Center for Supercomputing Applications UrbanaIL61801 United States DARK Niels Bohr Institute University of Copenhagen Jagtvej 128 Copenhagen2200 Denmark Gemini Observatory NSF's NOIRLab 670 N. A'ohoku Place HiloHI96720 United States Institute of Astronomy Kavli Institute for Cosmology Madingley Road CambridgeCB3 0HA United Kingdom Department of Astronomy and Astrophysics The Pennsylvania State University Davey Lab State College PA16802 United States Institute for Computational & Data Sciences The Pennsylvania State University University ParkPA United States Institute for Gravitation and the Cosmos The Pennsylvania State University University ParkPA16802 United States Institute for Astronomy University of Hawaii 2680 Woodlawn Drive HonoluluHI96822 United States Department of Physics and Astronomy The Johns Hopkins University BaltimoreMD21218 United States ISEF International Fellowship

We present pre-explosion optical and infrared (IR) imaging at the site of the type II supernova (SN II) 2023ixf in Messier 101 at 6.9 Mpc. We astrometrically registered a ground-based image of SN 2023ixf to archival Hubble Space Telescope (HST), Spitzer Space Telescope (Spitzer), and ground-based near-IR images. A single point source is detected at a position consistent with the SN at wavelengths ranging from HST R-band to Spitzer 4.5 µm. Fitting to blackbody and red supergiant (RSG) spectral-energy distributions (SEDs), we find that the source is anomalously cool with a significant mid-IR excess. We interpret this SED as reprocessed emission in a 8600 R☉ circumstellar shell of dusty material with a mass ∼5×10−5 M☉ surrounding a log(L/L☉) = 4.74 ±0.07 and Teff = 3920+200−160 K RSG. This luminosity is consistent with RSG models of initial mass 11 M☉, depending on assumptions of rotation and overshooting. In addition, the counterpart was significantly variable in pre-explosion Spitzer 3.6 µm and 4.5 µm imaging, exhibiting ∼70% variability in both bands correlated across 9 yr and 29 epochs of imaging. The variations appear to have a timescale of 2.8 yr, which is consistent with κ-mechanism pulsations observed in RSGs, albeit with a much larger amplitude than RSGs such as α Orionis (Betelgeuse). © 2023, CC BY.

关键词： Supernovae