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A light in the dark: searching for electromagnetic counterparts to black hole-black hole mergers in LIGO/Virgo O3 with the Zwicky Transient Facility

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arXiv 2022年

作者： Graham, Matthew J. McKernan, Barry Ford, K.E. Saavik Stern, Daniel Djorgovski, S.G. Coughlin, Michael Burdge, Kevin B. Bellm, Eric C. Helou, George Mahabal, Ashish A. Masci, Frank J. Purdum, Josiah Rosnet, Philippe Rusholme, Ben California Institute of Technology 1200 E. California Blvd PasadenaCA91125 United States Department of Science CUNY Borough of Manhattan Community College 199 Chambers Street New YorkNY10007 United States Department of Astrophysics American Museum of Natural History Central Park West New YorkNY10028 United States Physics Program CUNY Graduate Center 365 5th Avenue New YorkNY10016 United States Center for Computational Astrophysics Flatiron Institute New YorkNY10010 United States Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States School of Physics and Astronomy University of Minnesota MinneapolisMN55455 United States Department of Physics Massachusetts Institute of Technology CambridgeMA02139 United States Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology CambridgeMA02139 United States DIRAC Institute Department of Astronomy University of Washington 3910 15th Avenue NE SeattleWA98195 United States IPAC California Institute of Technology 1200 E. California Blvd PasadenaCA91125 United States Division of Physics Mathematics and Astronomy California Institute of Technology PasadenaCA91125 United States Center for Data Driven Discovery California Institute of Technology PasadenaCA91125 United States Caltech Optical Observatories California Institute of Technology PasadenaCA91125 United States Université Clermont Auvergne CNRS IN2P3 LPC Clermont-FerrandF-63000 France

The accretion disks of active galactic nuclei (AGN) are promising locations for the merger of compact objects detected by gravitational wave (GW) observatories. Embedded within a baryon-rich, high density environment, mergers within AGN are the only GW channel where an electromagnetic (EM) counterpart must occur (whether detectable or not). Considering AGN with unusual flaring activity observed by the Zwicky Transient Facility (ZTF), we describe a search for candidate EM counterparts to binary black hole (BBH) mergers detected by LIGO/Virgo in O3. After removing probable false positives, we find nine candidate counterparts to BBH mergers during O3 (seven in O3a, two in O3b) with a p-value of 0.0019. Based on ZTF sky coverage, AGN geometry, and merger geometry, we expect ≈ 3(NBBH/83)(fAGN/0.5) potentially detectable EM counterparts from O3, where NBBH is the total number of observed BBH mergers and fAGN is the fraction originating in AGN. Further modeling of breakout and flaring phenomena in AGN disks is required to reduce our false positive rate. Two of the events are also associated with mergers with total masses > 100M☉, which is the expected rate for O3 if hierarchical (large mass) mergers occur in the AGN channel. Candidate EM counterparts in future GW observing runs can be better constrained by coverage of the Southern sky as well as spectral monitoring of unusual AGN flaring events in LIGO/Virgo alert volumes. A future set of reliable AGN EM counterparts to BBH mergers will yield an independent means of measuring cosmic expansion (H0) as a function of redshift. © 2022, CC BY.

关键词： Gravity waves

The Hubble Space Telescope Survey of M31 Satellite Galaxies IV. Survey Overview and Lifetime Star Formation Histories

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arXiv 2025年

作者： Savino, Alessandro Weisz, Daniel R. Dolphin, Andrew E. Durbin, Meredith J. Kallivayalil, Nitya Wetzel, Andrew Anderson, Jay Besla, Gurtina Boylan-Kolchin, Michael Brown, Thomas M. Bullock, James S. Cole, Andrew A. Collins, Michelle L.M. Cooper, M.C. Deason, Alis J. Dotter, Aaron L. Fardal, Mark Ferguson, Annette M.N. Fritz, Tobias K. Geha, Marla C. Gilbert, Karoline M. Guhathakurta, Puragra Ibata, Rodrigo Irwin, Michael J. Jeon, Myoungwon Kirby, Evan N. Lewis, Geraint F. Mackey, Dougal Majewski, Steven R. Martin, Nicolas McConnachie, Alan Patel, Ekta Rich, R. Michael Skillman, Evan D. Simon, Joshua D. Sohn, Sangmo Tony Tollerud, Erik J. van der Marel, Roeland P. Department of Astronomy University of California Berkeley BerkeleyCA94720 United States Raytheon 1151 E. Hermans Road TucsonAZ85756 United States Steward Observatory University of Arizona 933 N. Cherry Avenue TucsonAZ85719 United States Department of Astronomy University of Virginia 530 McCormick Road CharlottesvilleVA22904 United States Department of Physics and Astronomy University of California DavisCA95616 United States Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Department of Astronomy University of Arizona 933 North Cherry Avenue TucsonAZ85721 United States Department of Astronomy The University of Texas at Austin 2515 Speedway Stop C1400 AustinTX78712 United States Department of Physics and Astronomy University of California IrvineCA92697 United States School of Natural Sciences University of Tasmania Private Bag 37 HobartTAS7001 Australia Physics Department University of Surrey GuildfordGU2 7XH United Kingdom Institute for Computational Cosmology Department of Physics Durham University DurhamDH1 3LE United Kingdom Department of Physics and Astronomy Dartmouth College 6127 Wilder Laboratory HanoverNH03755 United States Eureka Scientific 2452 Delmer St. Suite 100 OaklandCA96402 United States Institute for Astronomy University of Edinburgh Royal Observatory Blackford Hill EdinburghEH9 3HJ United Kingdom School of Data Science University of Virginia 1919 Ivy Road CharlottesvilleVA22903 United States Department of Astronomy Yale University New HavenCT06520 United States The William H. Miller III Department of Physics & Astronomy Bloomberg Center for Physics and Astronomy Johns Hopkins University 3400 N. Charles Street BaltimoreMD21218 United States UCO/Lick Observatory Department of Astronomy & Astrophysics University of California Santa Cruz 1156 High Street Santa CruzCA95064 United States Observatoire de Strasbourg 11 rue de l’Universite StrasbourgF-67000

From > 1000 orbits of HST imaging, we present deep homogeneous resolved star color-magnitude diagrams that reach the oldest main sequence turnoff and uniformly measured star formation histories (SFHs) of 36 dwarf galaxies (-6 ≥ MV ≥ -17) associated with the M31 halo, and for 10 additional fields in M31, M33, and the Giant Stellar Stream. From our SFHs we find: i) the median stellar age and quenching epoch of M31 satellites correlate with galaxy luminosity and galactocentric distance. Satellite luminosity and present-day distance from M31 predict the satellite quenching epoch to within 1.8 Gyr at all epochs. This tight relationship highlights the fundamental connection between satellite halo mass, environmental history, and star formation duration. ii) There is no difference between the median SFH of galaxies on and off the great plane of Andromeda satellites. iii) ∼ 50% of our M31 satellites show prominent ancient star formation (> 12 Gyr ago) followed by delayed quenching (8 - 10 Gyr ago), which is not commonly observed among the MW satellites. iv) A comparison with TNG50 and FIRE-2 simulated satellite dwarfs around M31-like hosts show that some of these trends (dependence of SFH on satellite luminosity) are reproduced in the simulations while others (dependence of SFH on galactocentric distance, presence of the delayed-quenching population) are weaker or absent. We provide all photometric catalogs and SFHs as High-Level Science Products on MAST. © 2025, CC BY.

关键词： Space telescopes

A High-Eccentricity Warm Jupiter Orbiting TOI-4127

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arXiv 2023年

作者： Gupta, Arvind F. Jackson, Jonathan M. Hébrard, Guillaume Lin, Andrea S.J. Stassun, Keivan G. Dong, Jiayin Villanueva, Steven Dragomir, Diana Mahadevan, Suvrath Wright, Jason T. Almenara, Jose M. Blake, Cullen H. Boisse, Isabelle Cortés-Zuleta, Pía Dalba, Paul A. Díaz, Rodrigo F. Ford, Eric B. Forveille, Thierry Gagliano, Robert Halverson, Samuel Heidari, Neda Kanodia, Shubham Kiefer, Flavien Latham, David W. McElwain, Michael W. Mireles, Ismael Moutou, Claire Pepper, Joshua Ricker, George R. Robertson, Paul Roy, Arpita Schlecker, Martin Schwab, Christian Seager, Sara Shporer, Avi Stefánsson, Guðmundur Terrien, Ryan C. Ting, Eric B. Winn, Joshua N. Youngblood, Allison Department of Astronomy & Astrophysics 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 Astronomy Department Van Vleck Observatory Wesleyan University 96 Foss Hill Drive MiddletownCT06459 United States Institut d’Astrophysique de Paris UMR7095 CNRS Université Pierre & Marie Curie 98bis boulevard Arago Paris75014 France Observatoire de Haute-Provence CNRS Université d’Aix-Marseille Saint-Michel-l’Observatoire04870 France Department of Physics and Astronomy Vanderbilt University NashvilleTN37235 United States Center for Computational Astrophysics Flatiron Institute 162 Fifth Avenue New YorkNY10010 United States Exoplanets and Stellar Astrophysics Laboratory NASA Goddard Space Flight Center GreenbeltMD20771 United States Department of Physics and Astronomy The University of New Mexico AlbuquerqueNM87106 United States ETH Zurich Institute for Particle Physics & Astrophysics Zurich Switzerland Penn State Extraterrestrial Intelligence Center 525 Davey Laboratory The Pennsylvania State University University ParkPA16802 United States Univ. Grenoble Alpes CNRS IPAG 414 rue de la Piscine St-Martin d’Hères38400 France Department of Physics and Astronomy University of Pennsylvania 209 S 33rd St PhiladelphiaPA19104 United States Aix Marseille Univ CNRS CNES LAM Marseille France Department of Astronomy and Astrophysics University of California Santa CruzCA95064 United States SETI Institute Carl Sagan Center 339 Bernardo Ave Suite 200 Mountain ViewCA94043 United States ECyT-UNSAM Campus Miguelete 25 de Mayo y Francia Buenos Aires1650 Argentina Institute for Computational and Data Sciences The Pennsylvania State University 525 Davey Laboratory University ParkPA16802 United States Center for Astrostatistics 525 Davey Laboratory The Pennsylvania State Un

We report the discovery of TOI-4127 b, a transiting, Jupiter-sized exoplanet on a long-period (P = 56.39879-0.00010+0.00010d), high-eccentricity orbit around a late F-type dwarf star. This warm Jupiter was first detected and identified as a promising candidate from a search for single-transit signals in TESS Sector 20 data, and later characterized as a planet following two subsequent transits (TESS Sectors 26 and 53) and follow-up ground-based RV observations with the NEID and SOPHIE spectrographs. We jointly fit the transit and RV data to constrain the physical (Rp = 1.096+0.039-0.032RJ, Mp = 2.30+0.11-0.11MJ) and orbital parameters of the exoplanet. Given its high orbital eccentricity (e = 0.7471+0.0078-0.0086), TOI-4127 b is a compelling candidate for studies of warm Jupiter populations and of hot Jupiter formation pathways. We show that the present periastron separation of TOI-4127 b is too large for high-eccentricity tidal migration to circularize its orbit, and that TOI-4127 b is unlikely to be a hot Jupiter progenitor unless it is undergoing angular momentum exchange with an undetected outer companion. Although we find no evidence for an external companion, the available observational data are insufficient to rule out the presence of a perturber that can excite eccentricity oscillations and facilitate tidal migration. © 2023, CC BY-NC-ND.

关键词： Extrasolar planets

Spintronic superconductor in a bulk layered material with natural spin-valve structure

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arXiv 2020年

作者： Sakuragi, Shunsuke Sasaki, S. Akashi, R. Sakagami, R. Kuroda, K. Bareille, C. Hashimoto, T. Nagashima, T. Kinoshita, Y. Hirata, Y. Shimozawa, M. Asai, S. Yajima, T. Doi, S. Tsujimoto, N. Kunisada, S. Noguchi, R. Kurokawa, K. Azuma, N. Hirata, K. Yamasaki, Y. Nakao, H. Kim, T.K. Cacho, C. Masuda, T. Tokunaga, M. Wadati, H. Okazaki, K. Shin, S. Kamihara, Y. Yamashita, Minoru Kondo, Takeshi Institute for Solid State Physics University of Tokyo Kashiwa Chiba Japan Department of Physics University of Tokyo Tokyo Japan Department of Applied Physics and Phisico-Informatics Keio University Yokohama Japan Department of Applied Physics National Defense Academy of Japan Yokosuka Japan Division of Materials Physics Graduate School of Engineering Science Osaka University Toyonaka Japan Research Center for Computational Design of Advanced Functional Materials National Institute of Advanced Industrial Science and Technology Tsukuba Japan Research and Services Division of Materials Data and Integrated System National Institute for Materials Science Tsukuba Japan RIKEN Center for Emergent Matter Science Wako Japan PRESTO Japan Science and Technology Agency Kawaguchi Japan Condensed Matter Research Center and Photon Factory Institute of Materials Structure Science High Energy Accelerator Research Organization Tsukuba Japan Diamond Light Source Harwell Campus Didcot United Kingdom Graduate School of Material Science University of Hyogo Hyogo Japan TheUniversity of Tokyo Kashiwa Chiba277-8581 Japan Center for Spintronics Research Network Keio University Yokohama Japan

Multi-layered materials provide fascinating platforms to realize various functional properties, possibly leading to future electronic devices controlled by external fields. In particular, layered magnets coupled with conducting layers have been extensively studied recently for possible control of their transport properties via the spin structure. Successful control of quantum-transport properties in the materials with antiferromagnetic (AFM) layers, so-called natural spin-valve structure, has been reported for the Dirac Fermion and topological/axion materials [1-11]. However, a bulk crystal in which magnetic and superconducting layers are alternately stacked has not been realized until now, and the search for functional properties in it is an interesting yet unexplored field in material science. Here, we discover superconductivity providing such an ideal platform in EuSn2As2 with the van der Waals stacking of magnetic Eu layers and superconducting Sn-As layers, and present the first demonstration of a natural spin-valve effect on the superconducting current. Below the superconducting transition temperature (Tc), the electrical resistivity becomes zero in the in-plane direction. In contrast, it, surprisingly, remains finite down to the lowest temperature in the out-of-plane direction, mostly due to the structure of intrinsic magnetic Josephson junctions in EuSn2As2. The magnetic order of the Eu layers (or natural spin-valve) is observed to be extremely soft, allowing one to easy control of the out-of-plane to in-plane resistivities ratio from 1 to ∞ by weak external magnetic fields. The concept of multi-functional materials with stacked magnetic-superconducting layers will open a new pathway to develop novel spintronic devices with magnetically controllable superconductivity. Copyright © 2020, The Authors. All rights reserved.

关键词： Europium compounds

Ubiquitous broad-line emission and the relation between ionized gas outflows and Lyman continuum escape in Green Pea galaxies

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arXiv 2024年

作者： Amorín, R.O. Rodríguez-Henríquez, M. Fernández, V. Vílchez, J.M. Marques-Chaves, R. Schaerer, D. Izotov, Y.I. Firpo, V. Guseva, N. Jaskot, A.E. Komarova, L. Muñoz-Vergara, D. Oey, M.S. Bait, O. Carr, C. Chisholm, J. Ferguson, H. Flury, S.R. Giavalisco, M. Hayes, M.J. Henry, A. Ji, Z. King, W. Leclercq, F. Östlin, G. Pentericci, L. Saldana-Lopez, A. Thuan, T.X. Trebitsch, M. Wang, B. Worseck, G. Xu, X. Unidad Asociada al CSIC Plaza San Juan 1 TeruelE–44001 Spain Departamento de Astronomía Universidad de La Serena Avda. Juan Cisternas 1200 La Serena Chile Gemini Observatory 670 N. A’ohoku Place HiloHI96720 United States University of Michigan Department of Astronomy 323 West Hall 1085 S. University Ave Ann ArborMI48109 United States Instituto de Investigación Multidisciplinar de Investigación y Posgrado Universidad de La Serena Raúl Bitrán 1305 La Serena Chile Instituto de Astrofísica de Andalucía CSIC Apartado de correos 3004 GranadaE-18080 Spain Department of Astronomy University of Geneva 51 Chemin Pegasi Versoix1290 Switzerland Bogolyubov Institute for Theoretical Physics National Academy of Sciences of Ukraine 14-b Metrolohichna str. Kyiv03143 Ukraine Gemini Observatory NSF’s NOIRLab Casilla 603 La Serena Chile Department of Astronomy University of Massachusetts AmherstMA01003 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 Department of Astronomy The University of Texas at Austin 2515 Speedway Stop C1400 AustinTX78712-1205 United States Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Department of Astronomy Oskar Klein Centre Stockholm University StockholmSE-106 91 Sweden 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 INAF - Osservatorio Astronomico di Roma Via di Frascati 33 Monte Porzio Catone00078 Italy Astronomy Department University of Virginia P.O. Box 400325 CharlottesvilleVA22904-4325 United States Kapteyn Astronomical Institute University of Groningen P.O. Box 800 Groningen9700 AV Netherlands Department of Astronom

We report observational evidence of highly turbulent ionized gas kinematics in a sample of 20 Lyman continuum (LyC) emitters (LCEs) at low redshift (z ∼ 0.3). Detailed Gaussian modeling of optical emission line profiles in high-dispersion spectra consistently shows that both bright recombination and collisionally excited lines can be fitted as one or two narrow components with intrinsic velocity dispersion of σ ∼ 40-100 km s−1, in addition to a broader component with σ ∼ 100-300 km s−1, which contributes up to ∼40% of the total flux and is preferentially blueshifted from the systemic velocity. We interpret the narrow emission as highly ionized gas close to the young massive star clusters and the broader emission as a signpost of unresolved ionized outflows, resulting from massive stars and supernova feedback. We find a significant correlation between the width of the broad emission and the LyC escape fraction, with strong LCEs exhibiting more complex and broader line profiles than galaxies with weaker or undetected LyC emission. We provide new observational evidence supporting predictions from models and simulations;our findings suggest that gas turbulence and outflows resulting from strong radiative and mechanical feedback play a key role in clearing channels through which LyC photons escape from galaxies. We propose that the detection of blueshifted broad emission in the nebular lines of compact extreme emission-line galaxies can provide a new indirect diagnostic of Lyman photon escape, which could be useful to identify potential LyC leakers in the epoch of reionization with the JWST. Copyright © 2024, The Authors. All rights reserved.

关键词： Galaxies

Earths within Reach: Evaluation of Strategies for Mitigating Solar Variability using 3.5 years of NEID Sun-as-a-Star Observations

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arXiv 2024年

作者： Ford, Eric B. Bender, Chad F. Blake, Cullen H. Gupta, Arvind F. Kanodia, Shubham Lin, Andrea S.J. Logsdon, Sarah E. Luhn, Jacob K. Mahadevan, Suvrath Palumbo III, Michael L. Terrien, Ryan C. Wright, Jason T. Zhao, Jinglin Halverson, Samuel Hunting, Emily Robertson, Paul Roy, Arpita Stefánsson, Gu mundur Department of Astronomy and Astrophysics Penn State University 525 Davey Laboratory 251 Pollock Road University ParkPA16802 United States Center for Exoplanets and Habitable Worlds Penn State University 525 Davey Laboratory 251 Pollock Road University ParkPA16802 United States Institute for Computational and Data Sciences Penn State University ParkPA16802 United States Center for Astrostatistics Penn State University 525 Davey Laboratory 251 Pollock Road University ParkPA16802 United States Steward Observatory University of Arizona 933 N. Cherry Ave TucsonAZ85721 United States Department of Physics and Astronomy University of Pennsylvania 209 S 33rd St PhiladelphiaPA19104 United States U.S. National Science Foundation National Optical-Infrared Astronomy Research Laboratory 950 N. Cherry Ave. TucsonAZ85719 United States Earth and Planets Laboratory Carnegie Science 5241 Broad Branch Road NW WashingtonDC20015 United States Department of Physics & Astronomy The University of California Irvine IrvineCA92697 United States Carleton College One North College St. MN55057 United States Penn State Extraterrestrial Intelligence Center Penn State University 525 Davey Laboratory 251 Pollock Road University ParkPA16802 United States DTU Space National Space Institute Technical University of Denmark Elektrovej 328 LyngbyDK-2800 Kgs. Denmark Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Astrophysics & Space Institute Schmidt Sciences New YorkNY10011 United States Anton Pannekoek Institute for Astronomy University of Amsterdam Science Park 904 Amsterdam1098 XH Netherlands

We present the results of Sun-as-a-star observations by the NEID Solar Telescope at WIYN Observatory, spanning January 1, 2021 through June 30, 2024. We identify 117,060 observations which are unlikely to be significantly affected by weather, hardware or major calibration issues. We describe several high-level data products being made available to the community to aid in the interpretation and inter comparisons of NEID solar observations. Solar observations demonstrate excellent performance of NEID, including radial velocity (RV) accuracy and long-term stability of better than 0.37m s-1over 3.5 years, even though NEID was not originally designed or optimized for daytime observations of the Sun. Currently, intrinsic stellar variability is the primary barrier to detecting Earth-analog planets for most nearby, Sun-like stars. We present a comparison of the effectiveness of several methods proposed to mitigate the effects of solar variability on the Sun's estimated radial RV. We find that the Scalpels algorithm performs particularly well and substantially reduces the root mean square (RMS) solar RV from over 2m s-1to 0.277 m s-1. Even when training on a subset of days with NEID solar observations and testing on a held-out sample, the RMS of cleaned RV is 0.340-0.422 m s-1. This is significantly better than previous attempts at removing solar variability and suggests that the current generation of EPRV instruments are technically capable of detecting Earth-mass planets orbiting a solar twin if provided with sufficient observing time allocations (∼ 103 nights of observations). © 2024, CC BY-SA.

关键词： Stars

What affects the performance of POD for the simulation of heat transfer through building component?

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Journal of physics: Conference Series 2021年第1期2069卷

作者： Tianfeng Hou Staf Roels Hans Janssen KU Leuven Department of Civil Engineering Building Physics Section 3001 Leuven Belgium Data Assimilation Research Team RIKEN Center for Computational Science Kobe Japan RIKEN Prediction Science Laboratory Kobe Japan RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program Kobe Japan

The capability of the proper orthogonal decomposition for the simulation of heat transfer in building components is investigated via three applications: linear heat transfer (not coupled to mass transfer), mildly non-linear heat transfer (coupled to air and moisture transfer (hygroscopic)) and highly non-linear heat transfer (coupled to moisture transfer (capillary)). It is shown that increasing non-linearity leads to an increasing number of required construction modes. To further investigate the reason for this degrading performance of POD, the singular values' decay progress from the different training snapshots is addressed in this paper. The results confirm that a fast decay of the singular values implies a high interrelation of the snapshots and a better performance of the POD method.

关键词：

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

Fundamental physics Opportunities with the Next-Generation Event Horizon Telescope

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arXiv 2023年

作者： Ayzenberg, Dimitry Blackburn, Lindy Brito, Richard Britzen, Silke Broderick, Avery E. Carballo-Rubio, Raúl Cardoso, Vitor Chael, Andrew Chatterjee, Koushik Chen, Yifan Cunha, Pedro V.P. Davoudiasl, Hooman Denton, Peter B. Doeleman, Sheperd S. Eichhorn, Astrid Eubanks, Marshall Fang, Yun Foschi, Arianna Fromm, Christian M. Galison, Peter Ghosh, Sushant G. Gold, Roman Gurvits, Leonid I. Hadar, Shahar Held, Aaron Houston, Janice Hu, Yichao Johnson, Michael D. Kocherlakota, Prashant Natarajan, Priyamvada Olivares, Héctor Palumbo, Daniel Pesce, Dominic W. Rajendran, Surjeet Roy, Rittick Saurabh Shao, Lijing Tahura, Shammi Tamar, Aditya Tiede, Paul Vincent, Frédéric H. Visinelli, Luca Wang, Zhiren Wielgus, Maciek Xue, Xiao Yakut, Kadri Yang, Huan Younsi, Ziri Theoretical Astrophysics Eberhard-Karls Universität Tübingen TübingenD-72076 Germany Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Harvard University 20 Garden Street CambridgeMA02138 United States CENTRA Departamento de Física Instituto Superior Técnico – IST Universidade de Lisboa – UL Avenida Rovisco Pais 1 Lisboa1049-001 Portugal Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Perimeter Institute for Theoretical Physics 31 Caroline Street North WaterlooONN2L 2Y5 Canada Department of Physics and Astronomy University of Waterloo 200 University Avenue West WaterlooONN2L 3G1 Canada Waterloo Centre for Astrophysics University of Waterloo WaterlooONN2L 3G1 Canada CP3-Origins University of Southern Denmark Campusvej 55 Odense MDK-5230 Denmark Florida Space Institute University of Central Florida 12354 Research Parkway Partnership 1 OrlandoFL32826 United States Niels Bohr International Academy Niels Bohr Institute Blegdamsvej 17 Copenhagen2100 Denmark Princeton Gravity Initiative Jadwin Hall Princeton University PrincetonNJ08544 United States Department of Physics University of Maryland College ParkMD20742 United States Institute for Research in Electronics and Applied Physics University of Maryland College ParkMD20742 United States Harvard-Smithsonian Center for Astrophysics 60 Garden Street CambridgeMA02138 United States Campus de Santiago Aveiro3810-183 Portugal High Energy Theory Group Physics Department Brookhaven National Laboratory UptonNY11973 United States Asteroid Initiatives LLC United States Perimeter Institute for Theoretical Physics WaterlooONN2L2Y5 Canada Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Institut für Theoretische Physik und Astrophysik Universität Würzburg Emil-Fischer-Strasse 31 Würzburg97074 Germany Institut für Theoretische Physik Goethe Universität Frankfurt Max-von

The Event Horizon Telescope (EHT) Collaboration recently published the first images of the supermassive black holes in the cores of the Messier 87 and Milky Way galaxies. These observations have provided a new means to study supermassive black holes and probe physical processes occurring in the strong-field regime. We review the prospects of future observations and theoretical studies of supermassive black hole systems with the next-generation Event Horizon Telescope (ngEHT), which will greatly enhance the capabilities of the existing EHT array. These enhancements will open up several previously inaccessible avenues of investigation, thereby providing important new insights into the properties of supermassive black holes and their environments. This review describes the current state of knowledge for five key science cases, summarising the unique challenges and opportunities for fundamental physics investigations that the ngEHT will enable. Copyright © 2023, The Authors. All rights reserved.

关键词： Telescopes