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arXiv 2018年

作者： Ohyama, Y. Wada, T. Matsuhara, H. Takagi, T. Malkan, M. Goto, T. Egami, E. Lee, H.-M. Im, M. Kim, J.-H. Pearson, C. Inami, H. Oyabu, S. Usui, F. Burgarella, D. Mazyed, F. Imanishi, M. Jeong, W.-S. Miyaji, T. Tello, J. Díaz Nakagawa, T. Serjeant, S. Takeuchi, T.T. Toba, Y. White, G.J. Hanami, H. Ishigaki, T. Academia Sinica Institute of Astronomy and Astrophysics 11F of Astronomy-Mathematics Building AS/NTU No. 1 Sec. 4 Roosevelt Rd. Taipei10617 Taiwan Institute of Space and Astronautical Science Japan Aerospace Exploration Agency 3-1-1 Yoshinodai Chuo-ku Sagamihara Kanagawa252-5210 Japan Japan Space Forum Shin-Ochanomizu Urban Trinity Bldg. 2F 3-2-1 Kandasurugadai Chiyoda-ku Tokyo101-0062 Japan Division of Astronomy and Astrophysics University of California Los Angeles 430 Portola Plaza Box 951547 Los AngelesCA90095-1547 United States Dark Cosmology Centre Niels Bohr Institute University of Copenhagen Juliane Maries Vej 30 Copenhagen Ø2100 Denmark National Tsing hua University No. 101 Section 2 Kuang-Fu Road Hsinchu30013 Taiwan Steward Observatory University of Arizona 933 N. Cherry Ave TucsonAZ85721 United States Astronomy Program Department of Physics and Astronomy Seoul National University Shillim-Dong Kwanak-Gu Seoul151-742 Korea Republic of Subaru Telescope National Astronomical Observatory of Japan 650 North Aòhoku Place HiloHI96720 United States RAL Space STFC Rutherford Appleton Laboratory Chilton Didcot OxfordshireOX11 0QX United Kingdom Department of Physics and Astronomy Open University Walton Hall Milton KeynesMK7 6AA United Kingdom Oxford Astrophysics Denys Wilkinson Building University of Oxford Keble Rd OxfordOX1 3RH United Kingdom National Optical Astronomy Observatory 950 North Cherry Avenue TucsonAZ85719 United States CRAL Observatoire de Lyon 9 avenue Charles André Saint Genis Laval69561 France Graduate School of Science Nagoya University Furo-cho Chikusa-ku Nagoya Aichi464-8602 Japan Graduate School of Science University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Center for Planetary Science Graduate School of Science Kobe University 7-1-48 Minatojima-Minamimachi Chuo-Ku Kobe650-0047 Japan Laboratoire d’Astrophysique de Marseille Pôle de l’Étoile Site de Château-Gombert 38 rue F

Context. Deep mid-infrared (MIR) surveys have revealed numerous strongly star-forming galaxies at redshift z . 2. Their MIR fluxes are produced by a combination of continuum and Polycyclic Aromatic Hydrocarbon (PAH) emission features. The PAH features can dominate the total MIR flux, but are difficult to measure without spectroscopy. Aims. We aim to study star-forming galaxies by using a blind spectroscopic survey at MIR wavelengths to understand evolution of their star formation rate (SFR) and specific SFR (SFR per stellar mass) up to z ' 0.5, by paying particular attention to their PAH properties. Methods. We conducted a low-resolution (R ' 50) slitless spectroscopic survey at 5–13 µm of 9 µm flux-selected sources (> 0.3 mJy) around the North Ecliptic Pole with the Infrared Camera (IRC) onboard AKARI. After removing 11 AGN candidates by using the IRC photometry, we identified 48 PAH galaxies with PAH 6.2, 7.7, and 8.6 µm features at z Copyright © 2018, The Authors. All rights reserved.

关键词： Polycyclic aromatic hydrocarbons

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Effects of galaxy environment on merger fraction

arXiv

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arXiv 2024年

作者： Pearson, W.J. Santos, D.J.D. Goto, T. Huang, T.-C. Kim, S.J. Matsuhara, H. Pollo, A. Ho, S.C.-C. Hwang, H.S. Malek, K. Nakagawa, T. Romano, M. Serjeant, S. Suelves, L. Shim, H. White, G.J. National Centre for Nuclear Research Pasteura 7 Warszawa02-093 Poland Max Planck Institute for Extraterrestrial Physics Giesenbachstrase 1 GarchingD-85748 Germany Institute of Astronomy National Tsing Hua University 101 Section 2. Kuang-Fu Road Hsinchu30013 Taiwan Department of Space and Astronautical Science Graduate University for Advanced Studies SOKENDAI Shonankokusaimura Hayama Miura District Kanagawa240-0193 Japan Institute of Space and Astronautical Science Japan Aerospace Exploration Agency 3-1-1 Yoshinodai Chuo-ku Sagamihara Kanagawa252-5210 Japan Research School of Astronomy and Astrophysics The Australian National University CanberraACT2611 Australia Centre for Astrophysics and Supercomputing Swinburne University of Technology P.O. Box 218 HawthornVIC3122 Australia OzGrav: The Australian Research Council Centre of Excellence for GravitationalWave Discovery HawthornVIC3122 Australia ASTRO3D: The Australian Research Council Centre of Excellence for All-sky Astrophysics in 3D ACT2611 Australia Astronomy Program Department of Physics and Astronomy Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of SNU Astronomy Research Center Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of INAF-Osservatorio Astronomico di Padova Vicolo dell'Osservatorio 5 PadovaI-35122 Italy School of Physical Sciences The Open University Walton Hall Milton KeynesMK7 6AA United Kingdom Department of Earth Science Education Kyungpook National University 80 Daehak-ro Buk-gu Daegu41566 Korea Republic of Space Science and Technology Division RALSpace STFC Rutherford Appleton Laboratory Chilton DidcotOX11 0QX United Kingdom

Aims. In this work, we intend to examine how environment influences the merger fraction, from the low density field environment to higher density groups and clusters. We also aim to study how the properties of a group or cluster, as well as the position of a galaxy in the group or cluster, influences the merger fraction. *** identified galaxy groups and clusters in the North Ecliptic Pole using a friends-of-friends algorithm and the local density. Once identified, we determined the central galaxies, group radii, velocity dispersions, and group masses of these groups and clusters. Merging systems were identified with a neural network as well as *** these, we examined how the merger fraction changes as the local density changes for all galaxies as well as how the merger fraction changes as the properties of the groups or clusters change. Results. We find that the merger fraction increases as local density increases and decreases as the velocity dispersion increases, as is often found in literature. A decrease in merger fraction as the group mass increases is also found. We also find groups with larger radii have higher merger fractions. The number of galaxies in a group does not influence the merger fraction. Conclusions. The decrease in merger fraction as group mass increases is a result of the link between group mass and velocity dispersion. Hence, this decrease of merger fraction with increasing mass is a result of the decrease of merger fraction with velocity dispersion. The increasing relation between group radii and merger fraction may be a result of larger groups having smaller velocity dispersion at a larger distance from the centre or larger groups hosting smaller, infalling groups with more mergers. However, we do not find evidence of smaller groups having higher merger fractions. Copyright © 2024, The Authors. All rights reserved.

关键词： Galaxies

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Direct Imaging Discovery and Dynamical Mass of a Substellar Companion Orbiting an Accelerating Hyades Sun-like Star with SCExAO/CHARIS

arXiv

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arXiv 2022年

作者： Kuzuhara, Masayuki Currie, Thayne Takarada, Takuya Brandt, Timothy D. Sato, Bun'ei Uyama, Taichi Janson, Markus Chilcote, Jeffrey Tobin, Taylor Lawson, Kellen Hori, Yasunori Guyon, Olivier Groff, Tyler D. Lozi, Julien Vievard, Sebastien Sahoo, Ananya Deo, Vincent Jovanovic, Nemanja Ahn, Kyohoon Martinache, Frantz Skaf, Nour Akiyama, Eiji Norris, Barnaby R. Bonnefoy, Mickaël Helminiak, Krzysztof G. Kudo, Tomoyuki McElwain, Michael W. Samland, Matthias Wagner, Kevin Wisniewski, John Knapp, Gillian R. Kwon, Jungmi Nishikawa, Jun Serabyn, Eugene Hayashi, Masahiko Tamura, Motohide Astrobiology Center of NINS 2-21-1 Osawa Mitaka Tokyo181-8588 Japan National Astronomical Observatory of Japan 2-21-2 Osawa Mitaka Tokyo181-8588 Japan Subaru Telescope National Astronomical Observatory of Japan 650 North A'ohōkū Place HiloHI96720 United States NASA-Ames Research Center Moffett Blvd. Moffett Field CA United States Eureka Scientific 2452 Delmer Street Suite 100 OaklandCA United States Department of Physics University of California Santa Barbara Santa BarbaraCA United States Department of Earth and Planetary Sciences School of Science Tokyo Institute of Technology 2-12-1 Ookayama Meguro-ku Tokyo152-8551 Japan Infrared Processing and Analysis Center California Institute of Technology PasadenaCA91125 United States Department of Astronomy Stockholm University Stockholm Sweden Department of Physics University of Notre Dame Notre DameIN United States Homer S Dodge Department of Physics and Astronomy University of Oklahoma NormanOK United States Department of Astronomical Science The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Steward Observatory The University of Arizona TucsonAZ85721 United States College of Optical Sciences University of Arizona TucsonAZ85721 United States NASA-Goddard Space Flight Center GreenbeltMD United States Department of Astronomy California Institute of Technology 1200 E. California Blvd. PasadenaCA91125 United States Université Côte d'Azur Observatoire de la Côte d'Azur CNRS Laboratoire Lagrange France LESIA Observatoire de Paris Univ. PSL CNRS Sorbonne Univ. Univ. de Paris 5 pl. Jules Janssen Meudon92195 France Division of Fundamental Education and Liberal Arts Department of Engineering Niigata Institute of Technology 1719 Fujihashi Niigata Kashiwazaki945-1195 Japan Sydney Institute for Astronomy School of Physics University of Sydney SydneyNSW Australia Institut de Planétologie et d'Astrophysique de Grenoble CNRS IPAG Franc

We present the direct-imaging discovery of a substellar companion in orbit around a Sun-like star member of the Hyades open cluster. So far, no other substellar companions have been unambiguously confirmed via direct imaging around main-sequence stars in Hyades. The star HIP 21152 is an accelerating star as identified by the astrometry from the Gaia and Hipparcos satellites. We have detected the companion, HIP 21152 B, in multi-epoch using the high-contrast imaging from SCExAO/CHARIS and Keck/NIRC2. We have also obtained the stellar radial-velocity data from the Okayama 188cm telescope. The CHARIS spectroscopy reveals that HIP 21152 B's spectrum is consistent with the L/T transition, best fit by an early T dwarf. Our orbit modeling determines the semi-major axis and the dynamical mass of HIP 21152 B to be (Equation presented) au and (Equation presented) MJup, respectively. The mass ratio of HIP 21152 B relative to its host is ≈2%, near the planet/brown dwarf boundary suggested from recent surveys. Mass estimates inferred from luminosity evolution models are slightly higher (33-42 MJup). With a dynamical mass and a well-constrained age due to the system's Hyades membership, HIP 21152 B will become a critical benchmark in understanding the formation, evolution, and atmosphere of a substellar object as a function of mass and age. Our discovery is yet another key proof-of-concept for using precision astrometry to select direct imaging targets. Copyright © 2022, The Authors. All rights reserved.

关键词： Stars

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26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 Antwerp, Belgium. 15-20 July 2017 Abstracts

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BMC NEUROscience 2017年第SUPPL 1期18卷 95-176页

作者： [Anonymous] Department of Neuroscience Yale University New Haven CT 06520 USA Department Physiology & Pharmacology SUNY Downstate Brooklyn NY 11203 USA NYU School of Engineering 6 MetroTech Center Brooklyn NY 11201 USA Departament de Matemàtica Aplicada Universitat Politècnica de Catalunya Barcelona 08028 Spain Institut de Neurobiologie de la Méditerrannée (INMED) INSERM UMR901 Aix-Marseille Univ Marseille France Center of Neural Science New York University New York NY USA Aix-Marseille Univ INSERM INS Inst Neurosci Syst Marseille France Laboratoire de Physique Théorique et Modélisation CNRS UMR 8089 Université de Cergy-Pontoise 95300 Cergy-Pontoise Cedex France Department of Mathematics and Computer Science ENSAT Abdelmalek Essaadi’s University Tangier Morocco Laboratory of Natural Computation Department of Information and Electrical Engineering and Applied Mathematics University of Salerno 84084 Fisciano SA Italy Department of Medicine University of Salerno 84083 Lancusi SA Italy Dipartimento di Fisica Università degli Studi Aldo Moro Bari and INFN Sezione Di Bari Italy Data Analysis Department Ghent University Ghent Belgium Coma Science Group University of Liège Liège Belgium Cruces Hospital and Ikerbasque Research Center Bilbao Spain BIOtech Department of Industrial Engineering University of Trento and IRCS-PAT FBK 38010 Trento Italy Department of Data Analysis Ghent University Ghent 9000 Belgium The Wellcome Trust Centre for Neuroimaging University College London London WC1N 3BG UK Department of Electronic Engineering NED University of Engineering and Technology Karachi Pakistan Blue Brain Project École Polytechnique Fédérale de Lausanne Lausanne Switzerland Departement of Mathematics Swansea University Swansea Wales UK Laboratory for Topology and Neuroscience at the Brain Mind Institute École polytechnique fédérale de Lausanne Lausanne Switzerland Institute of Mathematics University of Aberdeen Aberdeen Scotland UK Department of Integrativ

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Magnetic Fields in Massive Star-forming Regions (MagMaR): Unveiling an Hourglass Magnetic Field in G333.46−0.16 using ALMA

arXiv

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arXiv 2024年

作者： Saha, Piyali Sanhueza, Patricio Padovani, Marco Girart, Josep M. Cortes, Paulo Morii, Kaho Liu, Junhao Sánchez-Monge, Á. Galli, Daniele Basu, Shantanu Koch, Patrick M. Beltrán, Maria T. Li, Shanghuo Beuther, Henrik Stephens, Ian W. Nakamura, Fumitaka Zhang, Qizhou Jiao, Wenyu Fernández-López, M. Hwang, Jihye Chung, Eun Jung Pattle, Kate Zapata, Luis A. Xu, Fengwei Olguin, Fernando A. Kang, Ji-Hyun Karoly, Janik Law, Chi-Yan Wang, Jia-Wei Csengeri, Timea Lu, Xing Cheng, Yu Kim, Jongsoo Choudhury, Spandan Chen, Huei-Ru Vivien Hull, Charles L.H. National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan INAF-Osservatorio Astrofisico di Arcetri Largo E. Fermi 5 Firenze50125 Italy Campus UAB Can Magrans S/N Cerdanyola del Vallés CataloniaE-08193 Spain PMT-UPC Esteve Terradas 1 Castelldefels CataloniaE-08860 Spain Joint ALMA Observatory Alonso de Córdova 3107 Vitacura Santiago Chile National Radio Astronomy Observatory 520 Edgemont Road CharlottesvilleVA22903 United States Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Department of Physics and Astronomy University of Western Ontario LondonONN6A 3K7 Canada Academia Sinica Institute of Astronomy and Astrophysics Taipei Taiwan INAF-Osservatorio Astrofisico di Arcetri Largo E. Fermi 5 FirenzeI-50125 Italy Max Planck Institute for Astronomy Königstuhl 17 HeidelbergD-69117 Germany Department of Earth Environment and Physics Worcester State University WorcesterMA01602 United States Department of Astronomy The University of Tokyo Hongo Tokyo113-0033 Japan 2-21-1 Osawa Mitaka Tokyo181-0015 Japan Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Department of Astronomy School of Physics Peking University Beijing100871 China Kavli Institute for Astronomy and Astrophysics Peking University Haidian District Beijing100871 China C.C. No. 5 Villa Elisa Buenos Aires1894 Argentina Korea Astronomy and Space Science Institute 776 Daedeokdae-ro Yuseong-gu Daejeon34055 Korea Republic of Department of Physics and Astronomy University College London Gower Street LondonWC1E 6BT United Kingdom Instituto de Radioastronomía y Astrofísica Universidad Nacional Autónoma de México P.O. Box 3-72 Michoacán Morelia58090 Mexico

The contribution of the magnetic field to the formation of high-mass stars is poorly understood. We report the high-angular resolution (∼ 0.3′′, 870 au) map of the magnetic field projected on the plane of the sky (Bpos) towards the high-mass star forming region G333.46−0.16 (G333), obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) at 1.2 mm as part of the Magnetic Fields in Massive Star-forming Regions (MagMaR) survey. The Bpos morphology found in this region is consistent with a canonical "hourglass" which suggest a dynamically important field. This region is fragmented into two protostars separated by ∼ 1740 au. Interestingly, by analysing H13CO+ (J = 3−2) line emission, we find no velocity gradient over the extend of the continuum which is consistent with a strong field. We model the Bpos, obtaining a marginally supercritical mass-to-flux ratio of 1.43, suggesting a initially strongly magnetized environment. Based on the Davis–Chandrasekhar–Fermi method, the magnetic field strength towards G333 is estimated to be 5.7 mG. The absence of strong rotation and outflows towards the central region of G333 suggests strong magnetic braking, consistent with a highly magnetized environment. Our study shows that despite being a strong regulator, the magnetic energy fails to prevent the process of fragmentation, as revealed by the formation of the two protostars in the central region. Copyright © 2024, The Authors. All rights reserved.

关键词： Magnetic fields

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The ALCHEMI atlas: principal component analysis reveals starburst evolution in NGC 253

arXiv

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arXiv 2024年

作者： Harada, Nanase Meier, David S. Martín, Sergio Muller, Sebastien Sakamoto, Kazushi Saito, Toshiki Gorski, Mark D. Henkel, Christian Tanaka, Kunihiko Mangum, Jeffrey G. Aalto, Susanne Aladro, Rebeca Bouvier, Mathilde Colzi, Laura Emig, Kimberly L. Herrero-Illana, Rubén Huang, Ko-Yun Kohno, Kotaro König, Sabine Nakanishi, Kouichiro Nishimura, Yuri Takano, Shuro Rivilla, Víctor M. Viti, Serena Watanabe, Yoshimasa van der Werf, Paul P. Yoshimura, Yuki National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Institute of Astronomy and Astrophysics Academia Sinica 11F of AS/NTU Astronomy-Mathematics Building No.1 Sec. 4 Roosevelt Rd Taipei10617 Taiwan Astronomical Science Program Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-1855 Japan New Mexico Institute of Mining and Technology 801 Leroy Place SocorroNM87801 United States National Radio Astronomy Observatory PO Box O 1003 Lopezville Road SocorroNM87801 United States European Southern Observatory Alonso de Córdova 3107 Vitacura Santiago763-0355 Chile Joint ALMA Observatory Alonso de Córdova 3107 Vitacura Santiago763-0355 Chile Department of Space Earth and Environment Chalmers University of Technology Onsala Space Observatory OnsalaSE-439 92 Sweden Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 Bonn53121 Germany Astronomy Department Faculty of Science King Abdulaziz University P. O. Box 80203 Jeddah21589 Saudi Arabia Department of Physics Faculty of Science and Technology Keio University 3-14-1 Hiyoshi Kanagawa Yokohama223-8522 Japan National Radio Astronomy Observatory 520 Edgemont Road CharlottesvilleVA22903-2475 United States Department of Space Earth and Environment Chalmers University of Technology GöteborgSE-412 96 Sweden Leiden Observatory Leiden University P.O. Box 9513 Leiden2300 RA Netherlands CSIC-INTA Ctra. de Ajalvir Km. 4 Torrejón de Ardoz Madrid28850 Spain Campus UAB Carrer de Magrans BarcelonaE-08193 Spain Institute of Astronomy Graduate School of Science The University of Tokyo 2-21-1 Osawa Mitaka Tokyo181-0015 Japan Department of Astronomy The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan ALMA Project National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Department of Physic

Molecular lines are powerful diagnostics of the physical and chemical properties of the interstellar medium (ISM). These ISM properties, which affect future star formation, are expected to differ in starburst galaxies from those of more quiescent galaxies. We investigate the ISM properties in the central molecular zone of the nearby starburst galaxy NGC 253 using the ultra-wide millimeter spectral scan survey from the ALMA Large program ALCHEMI. We present an atlas of velocity-integrated images at a 1′′. 6 resolution of 148 unblended transitions from 44 species, including the first extragalactic detection of HCNH+ and the first interferometric images of C3H+, NO, HCS+. We conduct a principal component analysis (PCA) on these images to extract correlated chemical species and to identify key groups of diagnostic transitions. To the best of our knowledge, our dataset is currently the largest astronomical set of molecular lines to which PCA has been applied. The PCA can categorize transitions coming from different physical components in NGC 253 such as i) young starburst tracers characterized by high-excitation transitions of HC3N and complex organic molecules (COMs) versus tracers of on-going star formation (radio recombination lines) and high-excitation transitions of CCH and CN tracing PDRs, ii) tracers of cloud-collision-induced shocks (low-excitation transitions of CH3OH, HNCO, HOCO+, and OCS) versus shocks from star-formation-induced outflows (high-excitation transitions of SiO), as well as iii) outflows showing emission from HOC+, CCH, H3O+, CO isotopologues, HCN, HCO+, CS, and CN. Our findings show these intensities vary with galactic dynamics, star formation activities, and stellar feedback. © 2024, CC BY.

关键词： Principal component analysis

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A Fourth Planet in the Kepler-51 System Revealed by Transit Timing Variations

arXiv

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arXiv 2024年

作者： Masuda, Kento Libby-Roberts, Jessica E. Livingston, John H. Stevenson, Kevin B. Gao, Peter Vissapragada, Shreyas Fu, Guangwei Han, Te Greklek-McKeon, Michael Mahadevan, Suvrath Agol, Eric Bello-Arufe, Aaron Berta-Thompson, Zachory Cañas, Caleb I. Chachan, Yayaati Hebb, Leslie Hu, Renyu Kawashima, Yui Knutson, Heather A. Morley, Caroline V. Murray, Catriona A. Ohno, Kazumasa Tokadjian, Armen Zhang, Xi Welbanks, Luis Nixon, Matthew C. Freedman, Richard Narita, Norio Fukui, Akihiko de Leon, Jerome P. Mori, Mayuko Palle, Enric Murgas, Felipe Parviainen, Hannu Esparza-Borges, Emma Jontof-Hutter, Daniel Collins, Karen A. Benni, Paul Barkaoui, Khalid Pozuelos, Francisco J. Gillon, Michaël Jehin, Emmanuël Benkhaldoun, Zouhair Hawley, Suzanne Lin, Andrea S.J. Stefánsson, Guðmundur Bieryla, Allyson Yilmaz, Mesut Senavci, Hakan Volkan Girardin, Eric Marino, Giuseppe Wang, Gavin Department of Earth and Space Science Osaka University Osaka560-0043 Japan 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 Astrobiology Center 2-21-1 Osawa Mitaka Tokyo181-8588 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Astronomical Science Program Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan JHU Applied Physics Laboratory 11100 Johns Hopkins Rd LaurelMD20723 United States Carnegie Science Earth and Planets Laboratory 5241 Broad Branch Road NW WashingtonDC20015 United States Carnegie Science Observatories 813 Santa Barbara Street PasadenaCA91101 United States Department of Physics and Astronomy Johns Hopkins University BaltimoreMD United States Department of Physics & Astronomy The University of California Irvine IrvineCA92697 United States Division of Geological and Planetary Sciences California Institute of Technology PasadenaCA91125 United States Department of Astronomy University of Washington SeattleWA98195 United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA91011 United States Department of Astrophysical and Planetary Sciences University of Colorado Boulder BoulderCO80309 United States NASA Goddard Space Flight Center 8800 Greenbelt Road GreenbeltMD20771 United States Department of Physics Trottier Space Institute McGill University 3600 rue University MontréalQCH3A 2T8 Canada Université de Montréal Quebec Canada Hobart and William Smith Colleges GenevaNY14456 United States Cornell University IthacaNY14853 United States Frontier Research Institute for Interdisciplinary Sciences Tohoku University 6-3 Aramaki aza Aoba Aoba-ku Sendai Miyagi980-8578 Japan Department o

Kepler-51 is a 1 Gyr-old Sun-like star hosting three transiting planets with radii ≈ 6–9 R and orbital periods ≈ 45–130 days. Transit timing variations (TTVs) measured with past Kepler and Hubble Space Telescope (HST) observations have been successfully modeled by considering gravitational interactions between the three transiting planets, yielding low masses and low mean densities ( 0.1 g/cm3) for all three planets. However, the transit time of the outermost transiting planet Kepler-51d recently measured by the James Webb Space Telescope (JWST) 10 years after the Kepler observations is significantly discrepant from the prediction made by the three-planet TTV model, which we confirmed with ground-based and follow-up HST observations. We show that the departure from the three-planet model is explained by including a fourth outer planet, Kepler-51e, in the TTV model. A wide range of masses ( MJup) and orbital periods ( 10 yr) are possible for Kepler-51e. Nevertheless, all the coplanar solutions found from our brute-force search imply masses 10 M for the inner transiting planets. Thus their densities remain low, though with larger uncertainties than previously estimated. Unlike other possible solutions, the one in which Kepler-51e is around the 2: 1 mean motion resonance with Kepler-51d implies low orbital eccentricities ( 0.05) and comparable masses (∼ 5 M) for all four planets, as is seen in other compact multi-planet systems. This work demonstrates the importance of long-term follow-up of TTV systems for probing longer period planets in a system. © 2024, CC BY.

关键词： Space telescopes

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Correction: The structural, vibrational, and mechanical properties of jammed packings of deformable particles in three dimensions

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Soft matter 2022年第19期18卷 3815页

作者： Dong Wang John D Treado Arman Boromand Blake Norwick Michael P Murrell Mark D Shattuck Corey S O'Hern Department of Mechanical Engineering & Materials Science Yale University New Haven Connecticut 06520 USA. corey.ohern@yale.edu. Integrated Graduate Program in Physical and Engineering Biology Yale University New Haven Connecticut 06520 USA. Department of Physics Yale University New Haven Connecticut 06520 USA. Department of Biomedical Engineering Yale University New Haven Connecticut 06520 USA. Systems Biology Institute Yale University West Haven Connecticut 06516 USA. Benjamin Levich Institute and Physics Department The City College of New York New York New York 10031 USA. Department of Applied Physics Yale University New Haven Connecticut 06520 USA.

Correction for 'The structural, vibrational, and mechanical properties of jammed packings of deformable particles in three dimensions' by Dong Wang , , 2021, , 9901-9915, DOI: 10.1039/D1SM01228B.

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A detailed time-resolved and energy-resolved spectro-polarimetric study of bright GRBs detected by AstroSat CZTI in its first year of operation

arXiv

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arXiv 2024年

作者： Gupta, Rahul Pandey, S.B. Gupta, S. Chattopadhayay, T. Bhattacharya, D. Bhalerao, V. Castro-Tirado, A.J. Valeev, A. Ror, A.K. Sharma, V. Racusin, J. Aryan, A. Iyyani, S. Vadawale, S. Astrophysics Science Division NASA Goddard Space Flight Center Mail Code 661 GreenbeltMD20771 United States NASA Postdoctoral Program Manora Peak Nainital263002 India Bhabha Atomic Research Center Maharashtra Mumbai400094 India Homi Bhabha National Institute Maharashtra Mumbai400094 India Kavli Institute of Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Department of Physics Ashoka University Haryana Sonipat131029 India Indian Institute of Technology Bombay Powai Maharashtra Mumbai400076 India Glorieta de la Astronomía s/n GranadaE-18008 Spain Departamento de Ingeniería de Sistemas y Automática Escuela de Ingenierías Universidad de Málaga C. Dr. Ortiz Ramos sn MálagaE-29071 Spain Special Astrophysical Observatory of Russian Academy of Sciences Nizhniy Arkhyz Russia University of Maryland Baltimore County BaltimoreMD21250 United States Center for Research and Exploration in Space Science and Technology NASA/GSFC GreenbeltMD20771 United States Graduate Institute of Astronomy National Central University 300 Jhongda Road Jhongli32001 Taiwan Indian Institute of Science Education and Research Kerala Thiruvananthapuram695551 India Physical Research Laboratory Thaltej Gujarat Ahmedabad380009 India

The radiation mechanism underlying the prompt emission remains unresolved and can be resolved using a systematic and uniform time-resolved spectro-polarimetric study. In this paper, we investigated the spectral, temporal, and polarimetric characteristics of five bright GRBs using archival data from AstroSat CZTI, Swift BAT, and Fermi GBM. These bright GRBs were detected by CZTI in its first year of operation, and their average polarization characteristics have been published in Chattopadhyay et al. (2022). In the present work, we examined the time-resolved (in 100-600 keV) and energyresolved polarization measurements of these GRBs with an improved polarimetric technique such as increasing the effective area and bandwidth (by using data from low-gain pixels), using an improved event selection logic to reduce noise in the double events and extend the spectral bandwidth. In addition, we also separately carried out detailed time-resolved spectral analyses of these GRBs using empirical and physical synchrotron models. By these improved time-resolved and energy-resolved spectral and polarimetric studies (not fully coupled spectro-polarimetric fitting), we could pin down the elusive prompt emission mechanism of these GRBs. Our spectro-polarimetric analysis reveals that GRB 160623A, GRB 160703A, and GRB 160821A have Poynting flux-dominated jets. On the other hand, GRB 160325A and GRB 160802A have baryonic-dominated jets with mild magnetization. Furthermore, we observe a rapid change in polarization angle by ∼ 90 degrees within the main pulse of very bright GRB 160821A, consistent with our previous results. Our study suggests that the jet composition of GRBs may exhibit a wide range of magnetization, which can be revealed by utilizing spectro-polarimetric investigations of the bright GRBs. Copyright © 2024, The Authors. All rights reserved.

关键词： Polarimeters

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OBSERVATIONS OF M31 AND M33 WITH THE FERMI LARGE AREA TELESCOPE: A GALACTIC CENTER EXCESS IN ANDROMEDA?

arXiv

引用

arXiv 2017年

作者： Ackermann, M. Ajello, M. Albert, A. Baldini, L. Ballet, J. Barbiellini, G. Bastieri, D. Bellazzini, R. Bissaldi, E. Bloom, E.D. Bonino, R. Bottacini, E. Brandt, T.J. Bregeon, J. Bruel, P. Buehler, R. Cameron, R.A. Caputo, R. Caragiulo, M. Caraveo, P.A. Cavazzuti, E. Cecchi, C. Charles, E. Chekhtman, A. Chiaro, G. Ciprini, S. Costanza, F. Cutini, S. D’Ammando, F. de Palma, F. Desiante, R. Digel, S.W. Di Lalla, N. Di Mauro, M. Di Venere, L. Favuzzi, C. Funk, S. Fusco, P. Gargano, F. Giglietto, N. Giordano, F. Giroletti, M. Glanzman, T. Green, D. Grenier, I.A. Guillemot, L. Guiriec, S. Hayashi, K. Hou, X. Jóhannesson, G. Kamae, T. Knödlseder, J. Kong, A.K.H. Kuss, M. la Mura, G. Larsson, S. Latronico, L. Li, J. Longo, F. Loparco, F. Lubrano, P. Maldera, S. Malyshev, D. Manfreda, A. Martin, P. Mazziotta, M.N. Michelson, P.F. Mirabal, N. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Ohsugi, T. Omodei, N. Orlando, E. Ormes, J.F. Paneque, D. Persic, M. Pesce-Rollins, M. Piron, F. Porter, T.A. Principe, G. Rainò, S. Rando, R. Razzano, M. Reimer, O. Sánchez-Conde, M. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Tanaka, K. Tibaldo, L. Torres, D.F. Troja, E. Uchiyama, Y. Wang, J.C. Wood, K.S. Wood, M. Zaharijas, G. Zhou, M. Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 United States Los Alamos National Laboratory Los AlamosNM87545 United States Università di Pisa Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Laboratoire AIM CEA-IRFU CNRS Université Paris Diderot Service d’Astrophysique CEA Saclay Gif sur YvetteF-91191 France Istituto Nazionale di Fisica Nucleare Sezione di Trieste TriesteI-34127 Italy Dipartimento di Fisica Università di Trieste TriesteI-34127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Padova PadovaI-35131 Italy Dipartimento di Fisica e Astronomia "G. Galilei" Università di Padova PadovaI-35131 Italy Istituto Nazionale di Fisica Nucleare Sezione di Pisa PisaI-56127 Italy Istituto Nazionale di Fisica Nucleare Sezione di Bari BariI-70126 Italy W. W. Hansen Experimental Physics Laboratory Kavli Institute for Particle Astrophysics and Cosmology Department of Physics SLAC National Accelerator Laboratory Stanford University StanfordCA94305 United States Istituto Nazionale di Fisica Nucleare Sezione di Torino TorinoI-10125 Italy Dipartimento di Fisica Università degli Studi di Torino TorinoI-10125 Italy NASA Goddard Space Flight Center GreenbeltMD20771 United States Laboratoire Univers et Particules de Montpellier Université Montpellier CNRS/IN2P3 MontpellierF-34095 France Laboratoire Leprince-Ringuet École polytechnique CNRS/IN2P3 PalaiseauF-91128 France Santa Cruz Institute for Particle Physics Department of Physics Department of Astronomy and Astrophysics University of California at Santa Cruz Santa CruzCA95064 United States Dipartimento di Fisica "M. Merlin" dell’Università e del Politecnico di Bari BariI-70126 Italy INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Milano via E. Bassini 15 MilanoI-20133 Italy Science Data Center RomaI-00133 Italy Istituto Nazionale di Fi

The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in the Milky Way (MW) and in other, external, star-forming galaxies. Using 2 yr of observations with the Fermi LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit has been derived for the other nearby galaxy M33. We revisited the gamma-ray emission in the direction of M31 and M33 using more than 7 yr of LAT Pass 8 data in the energy range 0.1−100 GeV, presenting detailed morphological and spectral analyses. M33 remains undetected, and we computed an upper limit of 2.0×10−12 erg cm−2 s−1 on the 0.1−100 GeV energy flux (95% confidence level). This revised upper limit remains consistent with the observed correlation between gamma-ray luminosity and star-formation rate tracers and implies an average CR density in M33 that is at most half of that of the MW. M31 is detected with a significance of nearly 10σ. Its spectrum is consistent with a power law with photon index Γ = 2.4±0.1stat+syst and a 0.1−100 GeV energy flux of (5.6±0.6stat+syst)×10−12 erg cm−2 s−1. M31 is detected to be extended with a 4σ significance. The spatial distribution of the emission is consistent with a uniform-brightness disk with a radius of 0◦.4 and no offset from the center of the galaxy, but nonuniform intensity distributions cannot be excluded. The flux from M31 appears confined to the inner regions of the galaxy and does not fill the disk of the galaxy or extend far from it. The gamma-ray signal is not correlated with regions rich in gas or star-formation activity, which suggests that the emission is not interstellar in origin, unless the energetic particles radiating in gamma rays do not originate in recent star formation. Alternative and nonexclusive interpretations are that the emission results from a population of millisecond pulsars dispersed in the bulge and disk of M31 by disrupted globular clusters or from

关键词： Galaxies

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