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arXiv 2024年

作者： Mai, Xiaofeng Liu, Tie Liu, Xunchuan Zhu, Lei Garay, Guido Goldsmith, Paul F. Juvela, Mika Liu, Hongli Mannfors, Emma Tej, Anandmayee Sanhueza, Patricio Li, Shanghuo Xu, Fengwei Semadeni, Enrique Vazquez Jiao, Wenyu Peng, Yaping Baug, T. Yang, Aiyuan Dewangan, Lokesh Bronfman, Leonardo Gómez, Gilberto C. Palau, Aina Lee, Chang Won Qin, Sheng-Li Tatematsu, Ken'ichi Chibueze, James O. Yang, Dongting Lu, Xing Luo, Qiuyi Gu, Qilao Issac, Namitha Zhang, Suinan Li, Pak-Shing Zhang, Bo Tóth, L. Viktor Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai200030 China School of Astronomy and Space Sciences University of Chinese Academy of Sciences No. 19A Yuquan Road Beijing100049 China Chinese Academy of Sciences South America Center for Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Departamento de Astronomía Universidad de Chile Las Condes Santiago7591245 Chile Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States Department of Physics University of Helsinki P.O. box 64 FI-00014 Finland Department of Astronomy Yunnan University Kunming650091 China Indian Institute of Space Science and Technology Thiruvananthapuram695 547 India 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 Max Planck Institute for Astronomy Königstuhl 17 HeidelbergD-69117 Germany Kavli Institute for Astronomy and Astrophysics Peking University 5 Yiheyuan Road Haidian District Beijing100871 China Instituto de Radioastronomía y Astrofísica Universidad Nacional Autónoma de México Antigua Carretera a Pátzcuaro 8701 Ex-Hda. San José de la Huerta Michoacán Morelia58089 Mexico Department of Astronomy School of Physics Peking University Beijing100871 China Department of Physics Faculty of Science Kunming University of Science and Technology Kunming650500 China S. N. Bose National Centre for Basic Sciences Block JD Sector III Salt Lake Kolkata700106 India National Astronomical Observatories Chinese Academy of Sciences A20 Datun Road Chaoyang District Beijing100101 China Physical Research Laboratory Navrangpura Ahmedabad380009 India Departamento de Astronomá Universidad de Chile Las Condes Santiago7591245 Chile Korea Astronomy and Space Scien

Only a handful of massive starless core candidates have been discovered so far, but none of them have been fully confirmed. Within the MM1 clump in the filamentary infrared dark cloud G34.43+0.24 that was covered by the ALMA-ATOMS survey at Band 3 (∼ 2'', 6000 au) and the ALMA-QUARKS survey at Band 6 (∼ 0.3'', 900 au), two prestellar core candidates MM1-C and E1 with masses of 71 and 20 Mo and radii of 2100-4400 au were discovered. The two cores show no obvious sign of star-formation activities. In particular, MM1-C is a very promising massive prestellar core candidate with a total gas mass of 71 Mo. Within MM1-C, we detected two extremely dense substructures, C1 and C2, as characterized by their high densities of nH2 ∼ 108-9cm-3. Moreover, evidence of further fragmentation in C2 was also revealed. We have detected the primordial fragmentation in the earliest stage of massive star formation, and we speculate that MM1-C would be the birthplace of a massive multiple system. However, we cannot fully rule out the possibility that the massive prestellar core MM1-C will just form a cluster of low-mass stars if it undergoes further fragmentation. Copyright © 2024, The Authors. All rights reserved.

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Search for extended sources in the galactic plane using 6 years of Fermi-Large area telescope pass 8 data above 10 GeV

arXiv

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arXiv 2017年

作者： Ackermann, M. Ajello, M. 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. Caragiulo, M. Caraveo, P.A. Castro, D. Cavazzuti, E. Cecchi, C. Charles, E. Chekhtman, A. Cheung, C.C. Chiaro, G. Ciprini, S. Cohen, J.M. Costantin, D. 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. Fegan, S.J. Ferrara, E.C. Franckowiak, A. Fukazawa, Y. Funk, S. Fusco, P. Gargano, F. Gasparrini, D. Giglietto, N. Giordano, F. Giroletti, M. Green, D. Grenier, I.A. Grondin, M.-H. Guillemot, L. Guiriec, S. Harding, A.K. Hays, E. Hewitt, J.W. Horan, D. Hou, X. Jóhannesson, G. Kamae, T. Kuss, M. la Mura, G. Larsson, S. Lemoine-Goumard, M. Li, J. Longo, F. Loparco, F. Lubrano, P. Magill, J.D. Maldera, S. Malyshev, D. Manfreda, A. Mazziotta, M.N. Michelson, P.F. Mitthumsiri, W. Mizuno, T. Monzani, M.E. Morselli, A. Moskalenko, I.V. Negro, M. Nuss, E. Ohsugi, T. Omodei, N. Orienti, M. Orlando, E. Ormes, J.F. Paliya, V.S. Paneque, D. Perkins, J.S. Persic, M. Pesce-Rollins, M. Petrosian, V. Piron, F. Porter, T.A. Principe, G. Rainò, S. Rando, R. Razzano, M. Razzaque, S. Reimer, A. Reimer, O. Reposeur, T. Sgrò, C. Simone, D. Siskind, E.J. Spada, F. Spandre, G. Spinelli, P. Suson, D.J. Tak, D. Thayer, J.B. Thompson, D.J. Torres, D.F. Tosti, G. Troja, E. Vianello, G. Wood, K.S. Wood, M. Deutsches Elektronen Synchrotron DESY ZeuthenD-15738 Germany Department of Physics and Astronomy Clemson University Kinard Lab of Physics ClemsonSC29634-0978 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 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 Fisica Nucleare Sezione di Perugia PerugiaI-06123 Italy Dipartimento di Fisica Università degli Studi di Perugia PerugiaI-06123 Italy College of Science George Mason University Fairfax VA22030 United States Naval Research Laboratory Washi

The spatial extension of a γ-ray source is an essential ingredient to determine its spectral properties as well as its potential multi-wavelength counterpart. The capability to spatially resolve γ-ray sources is greatly improved by the newly delivered Fermi-Large Area Telescope (LAT) Pass 8 event-level analysis which provides a greater acceptance and an improved point spread function, two crucial factors for the detection of extended sources. Here, we present a complete search for extended sources located within 7◦ from the Galactic plane, using 6 years of Fermi-LAT data above 10 GeV. We find 46 extended sources and provide their morphological and spectral characteristics. This constitutes the first catalog of hard Fermi-LAT extended sources, named the Fermi Galactic Extended Source Catalog, which allows a thorough study of the properties of the Galactic plane in the sub-TeV domain. Copyright © 2017, The Authors. All rights reserved.

关键词： Gamma rays

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The ALMA Survey of Star Formation and Evolution in Massive Protoclusters with Blue Profiles (ASSEMBLE): Core Growth, Cluster Contraction, and Primordial Mass Segregation

arXiv

引用

arXiv 2023年

作者： Xu, Fengwei Wang, Ke Liu, Tie Tang, Mengyao Evans, Neal J. Palau, Aina Morii, Kaho He, Jinhua Sanhueza, Patricio Liu, Hong-Li Stutz, Amelia Zhang, Qizhou Chen, Xi Li, Pak Shing Gómez, Gilberto C. Vázquez-Semadeni, Enrique Li, Shanghuo Mai, Xiaofeng Lu, Xing Liu, Meizhu Chen, Li Li, Chuanshou Shi, Hongqiong Ren, Zhiyuan Li, Di Garay, Guido Bronfman, Leonardo Dewangan, Lokesh Juvela, Mika Lee, Chang Won Zhang, S. Yue, Nannan Wang, Chao Ge, Yifei Jiao, Wenyu Luo, Qiuyi Zhou, J.-W. Tatematsu, Kenichi Chibueze, James O. Su, Keyun Sun, Shenglan Ristorcelli, I. Toth, L. Viktor Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Department of Astronomy School of Physics Peking University Beijing100871 China Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China Institute of Astrophysics School of Physics and Electronic Science Chuxiong Normal University Chuxiong675000 China Department of Astronomy The University of Texas at Austin 2515 Speedway Stop C1400 AustinTX78712-1205 United States Instituto de Radioastronomía y Astrofísica Universidad Nacional Autónoma de México Antigua Carretera a Pátzcuaro 8701 Ex-Hda. San José de la Huerta Morelia Michoacán58089 Mexico Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Chinese Academy of Sciences South AmericaCenterfor Astronomy National Astronomical Observatories CAS Beijing100101 China Departamento de Astronomía Universidad de Chile Las Condes Santiago7591245 Chile Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Department of Astronomy Yunnan University Kunming650091 China Departamento de Astronomía Universidad de Concepción Casilla 160-C Concepción Chile Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Center for Astrophysics Guangzhou University Guangzhou510006 China Peng Cheng Lab Shenzhen518066 China Max Planck Institute for Astronomy Königstuhl 17 HeidelbergD-69117 Germany National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China National Astronomical Observatories CAS 20A Datun Road Chaoyang District Beijing100101 China Research

The ALMA Survey of Star Formation and Evolution in Massive Protoclusters with Blue Profiles (ASSEMBLE) aims to investigate the process of mass assembly and its connection to high-mass star formation theories in protoclusters in a dynamic view. We observed 11 massive (Mclump 103 M☉), luminous (Lbol 104 L☉), and blue-profile (infall signature) clumps by ALMA with resolution of ∼2200–5500 au (median value of 3500 au) at 350 GHz (870 µm). 248 dense cores were identified, including 106 cores showing protostellar signatures and 142 prestellar core candidates. Compared to early-stage infrared dark clouds (IRDCs) by ASHES, the core mass and surface density within the ASSEMBLE clumps exhibited significant increment, suggesting concurrent core accretion during the evolution of the clumps. The maximum mass of prestellar cores was found to be 2 times larger than that in IRDCs, indicating that evolved protoclusters have the potential to harbor massive prestellar cores. The mass relation between clumps and their most massive core (MMCs) is observed in ASSEMBLE but not in IRDCs, which is suggested to be regulated by multiscale mass accretion. The mass correlation between the core clusters and their MMCs has a steeper slope compared to that observed in stellar clusters, which can be due to fragmentation of the MMC and stellar multiplicity. We observe a decrease in core separation and an increase in central concentration as protoclusters evolve. We confirm primordial mass segregation in the ASSEMBLE protoclusters, possibly resulting from gravitational concentration and/or gas accretion. © 2023, CC BY.

关键词： Segregation (metallography)

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Stellar population and structural properties of dwarf galaxies and young stellar systems in the M81 group∗

arXiv

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arXiv 2019年

作者： Okamoto, Sakurako Arimoto, Nobuo Ferguson, Annette M.N. Irwin, Mike J. Bernard, Edouard J. Utsumi, Yousuke Subaru Telescope National Astronomical Observatory of Japan 650 North A’ohoku Place HiloHI96720 United States National Astronomical Observatory of Japan Osawa 2-21-1 Mitaka Tokyo181-8588 Japan Graduate University for Advanced Studies Osawa 2-21-1 Mitaka Tokyo181-8588 Japan Astronomy Program Department of Physics and Astronomy Seoul National University 599 Gwanak-ro Gwanak-gu Seoul151-742 Korea Republic of Institute for Astronomy University of Edinburgh Royal Observatory Blackford Hill EdinburghEH9 3HJ United Kingdom Institute of Astronomy University of Cambridge Madingley Road CambridgeCB3 0HA United Kingdom Observatoire de la Côte d’Azur 96 Boulevard de l’Observatoire Nice06300 France Kavli Institute for Particle Astrophysics and Cosmology Stanford University Menlo ParkCA94025 United States Hiroshima Astrophysical Science Center Hiroshima University Kagamiyama 1-3-1 Higashi-HiroshimaHiroshima739-8526 Japan

We use Hyper Suprime-Cam on the Subaru Telescope to investigate the structural and photometric properties of early-type dwarf galaxies and young stellar systems at the center of the M81 Group. We have mapped resolved stars to ∼ 2 magnitudes below the tip of the red giant branch over almost 6.5 square degrees, corresponding to a projected area of 160 × 160kpc at the distance of M81. The resulting stellar catalogue enables a homogeneous analysis of the member galaxies with unprecedented sensitivity to low surface brightness emission. The radial profiles of the dwarf galaxies are well-described by Sersic and King profiles, and show no obvious signatures of tidal disruption. The measured radii for most of these systems are larger than the existing literature values and we find the total luminosity of IKN (MV,0 = −14.29) to be almost 3 magnitudes brighter than previously-thought. We identify new dwarf satellite candidates, d1006+69 and d1009+68, which we estimate to lie at a distance of 4.3 ± 0.2 Mpc and 3.5 ± 0.5 Mpc. With MV,0 = −8.91 ± 0.40 and [M/H] = −1.83 ± 0.28, d1006+69 is one of the faintest and most metal-poor dwarf satellites currently-known in the M81 Group. The luminosity functions of young stellar systems in the outlying tidal HI debris imply continuous star formation in the recent past and the existence of populations as young as 30 Myr old. We find no evidence for old RGB stars coincident with the young MS/cHeB stars which define these objects, supporting the idea that they are genuinely new stellar systems resulting from triggered star formation in gaseous tidal debris. Copyright © 2019, The Authors. All rights reserved.

关键词： Galaxies

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The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites

arXiv

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arXiv 2024年

作者： Spitzer, Fridolin Kleine, Thorsten Burkhardt, Christoph Hopp, Timo Yokoyama, Tetsuya Abe, Yoshinari Aléon, Jérôme OD. Alexander, Conel M. Amari, Sachiko Amelin, Yuri Bajo, Ken-Ichi Bizzarro, Martin Bouvier, Audrey Carlson, Richard W. Chaussidon, Marc Choi, Byeon-Gak Dauphas, Nicolas Davis, Andrew M. Rocco, Tommaso Di Fujiya, Wataru Fukai, Ryota Gautam, Ikshu Haba, Makiko K. Hibiya, Yuki Hidaka, Hiroshi Homma, Hisashi Hoppe, Peter Huss, Gary R. Ichida, Kiyohiro Iizuka, Tsuyoshi Ireland, Trevor R. Ishikawa, Akira Itoh, Shoichi Kawasaki, Noriyuki Kita, Noriko T. Kitajima, Kouki Komatani, Shintaro Krot, Alexander N. Liu, Ming-Chang Masuda, Yuki Morita, Mayu Moynier, Fréderic Motomura, Kazuko Nakai, Izumi Nagashima, Kazuhide Nguyen, Ann Nittler, Larry Onose, Morihiko Pack, Andreas Park, Changkun Piani, Laurette Qin, Liping Russell, Sara S. Sakamoto, Naoya Schönbächler, Maria Tafla, Lauren Tang, Haolan Terada, Kentaro Terada, Yasuko Usui, Tomohiro Wada, Sohei Wadhwa, Meenakshi Walker, Richard J. Yamashita, Katsuyuki Yin, Qing-Zhu Yoneda, Shigekazu Young, Edward D. Yui, Hiroharu Zhang, Ai-Cheng Nakamura, Tomoki Naraoka, Hiroshi Noguchi, Takaaki Okazaki, Ryuji Sakamoto, Kanako Yabuta, Hikaru Abe, Masanao Miyazaki, Akiko Nakato, Aiko Nishimura, Masahiro Okada, Tatsuaki Yada, Toru Yogata, Kasumi Nakazawa, Satoru Saiki, Takanao Tanaka, Satoshi Terui, Fuyuto Tsuda, Yuichi Watanabe, Sei-Ichiro Yoshikawa, Makoto Tachibana, Shogo Yurimoto, Hisayoshi Max Planck Institute for Solar System Research Justus-von-Liebig-Weg 3 Göttingen37077 Germany Department of Earth and Planetary Sciences Tokyo Institute of Technology Tokyo152-8551 Japan Graduate School of Engineering Materials Science and Engineering Tokyo Denki University Tokyo120-8551 Japan Institut de Minéralogie de Physique des Matériaux et de Cosmochimie Sorbonne Université Museum National d'Histoire Naturelle CNRS UMR 7590 IRD Paris75005 France Earth and Planets Laboratory Carnegie Institution for Science WashingtonDC20015 United States McDonnell Center for the Space Sciences and Physics Department Washington University 35 St. LouisMO63130 United States Geochemical Research Center The University of Tokyo Tokyo113-0033 Japan Guangzhou Institute of Geochemistry Chinese Academy of Sciences GD Guangzhou510640 China Departement of Natural History Sciences Hokkaido University Sapporo001-0021 Japan Centre for Star and Planet Formation Globe Institute University of Copenhagen Copenhagen1350 Denmark Bayerisches Geoinstitut Universität Bayreuth Bayreuth95447 Germany Université Paris Cité Institut de Physique du Globe de Paris CNRS Paris75005 France Department of Earth Science Education Seoul National University Seoul08826 Korea Republic of Department of the Geophysical Sciences Enrico Fermi Institute The University of Chicago 5734 South Ellis Avenue Chicago60637 United States Faculty of Geosciences and Geography University of Göttingen GöttingenD-37077 Germany Faculty of Science Ibaraki University Mito310-8512 Japan ISAS/JSEC JAXA Sagamihara252-5210 Japan Research Center for Advanced Science and Technology The University of Tokyo Tokyo153-8904 Japan Research Institute for Marine Resources Utilization Japan Agency for Marine-Earth Science and Technology Kanagawa237-0061 Japan Departement of Earth and Planetary Sciences Nagoya University Nagoya464-8601 Japan Osaka Application Laboratory SBUWDX Rigaku Corporation Osaka569-1

The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies. The CI chondrites incorporated these grains more efficiently, possibly because they formed at the end of the disk’s lifetime, when planetesimal formation was also triggered by photoevaporation of the disk. Isotopic variations among carbonaceous chondrites may thus reflect fractionation of distinct dust components from a common reservoir, implying CI chondrites/Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites. © 2024, CC BY.

关键词： Nickel

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Early Release science of the exoplanet WASP-39b with JWST NIRISS

arXiv

引用

arXiv 2022年

作者： Feinstein, Adina D. Radica, Michael Welbanks, Luis Murray, Catriona Anne Ohno, Kazumasa Coulombe, Louis-Philippe Espinoza, Néstor Bean, Jacob L. Teske, Johanna K. Benneke, Björn Line, Michael R. Rustamkulov, Zafar Saba, Arianna Tsiaras, Angelos Barstow, Joanna K. Fortney, Jonathan J. Gao, Peter Knutson, Heather A. MacDonald, Ryan J. Mikal-Evans, Thomas Rackham, Benjamin V. Taylor, Jake Parmentier, Vivien Batalha, Natalie M. Berta-Thompson, Zachory K. Carter, Aarynn L. Changeat, Quentin Dos Santos, Leonardo A. Gibson, Neale P. Goyal, Jayesh M. Kreidberg, Laura López-Morales, Mercedes Lothringer, Joshua D. Miguel, Yamila Molaverdikhani, Karan Moran, Sarah E. Morello, Giuseppe Mukherjee, Sagnick Sing, David K. Stevenson, Kevin B. Wakeford, Hannah R. Ahrer, Eva-Maria Alam, Munazza K. Alderson, Lili Allen, Natalie H. Batalha, Natasha E. Bell, Taylor J. Blecic, Jasmina Brande, Jonathan Caceres, Claudio Casewell, S.L. Chubb, Katy L. Crossfield, Ian J.M. Crouzet, Nicolas Cubillos, Patricio E. Decin, Leen Désert, Jean-Michel Harrington, Joseph Heng, Kevin Henning, Thomas Iro, Nicolas Kempton, Eliza M.-R. Kendrew, Sarah Kirk, James Krick, Jessica Lagage, Pierre-Olivier Lendl, Monika Mancini, Luigi Mansfield, Megan May, E.M. Mayne, N.J. Nikolov, Nikolay K. Palle, Enric Petit dit de la Roche, Dominique J.M. Piaulet, Caroline Powell, Diana Redfield, Seth Rogers, Laura K. Roman, Michael T. Roy, Pierre-Alexis Nixon, Matthew C. Schlawin, Everett Tan, Xianyu Tremblin, P. Turner, Jake D. Venot, Olivia Waalkes, William C. Wheatley, Peter J. Zhang, Xi Department of Astronomy & Astrophysics University of Chicago ChicagoIL United States NSF Graduate Research Fellow Department of Physics Institute for Research on Exoplanets Université de Montréal MontrealQC Canada School of Earth and Space Exploration Arizona State University TempeAZ United States NHFP Sagan Fellow Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO United States Department of Astronomy & Astrophysics University of California Santa Cruz Santa CruzCA United States Space Telescope Science Institute BaltimoreMD United States Department of Physics & Astronomy Johns Hopkins University BaltimoreMD United States Earth and Planets Laboratory Carnegie Institution for Science WashingtonDC United States Department of Earth and Planetary Sciences Johns Hopkins University BaltimoreMD United States Department of Physics and Astronomy University College London United Kingdom INAF - Osservatorio Astrofisico di Arcetri Largo E. Fermi 5 Firenze Italy School of Physical Sciences The Open University Milton Keynes United Kingdom Division of Geological and Planetary Sciences California Institute of Technology PasadenaCA United States Department of Astronomy University of Michigan Ann ArborMI United States Department of Astronomy Carl Sagan Institute Cornell University IthacaNY United States Max Planck Institute for Astronomy Heidelberg Germany Department of Earth Atmospheric and Planetary Sciences Massachusetts Institute of Technology CambridgeMA United States Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology CambridgeMA United States 51 Pegasi b Fellow Atmospheric Oceanic and Planetary Physics Department of Physics University of Oxford Oxford United Kingdom Université Côte d'Azur Observatoire de la Côte d'Azur CNRS Laboratoire Lagrange France Astrobiology Program UC Santa Cruz Santa CruzCA United States European Space Agency Space Telescope Science Institute Balti

Transmission spectroscopy provides insight into the atmospheric properties and consequently the formation history, physics, and chemistry of transiting exoplanets1. However, obtaining precise inferences of atmospheric properties from transmission spectra requires simultaneously measuring the strength and shape of multiple spectral absorption features from a wide range of chemical species2–4. This has been challenging given the precision and wavelength coverage of previous observatories5. Here, we present the transmission spectrum of the Saturn-mass exoplanet WASP-39 b obtained using the SOSS mode of the NIRISS instrument on the JWST. This spectrum spans 0.6–2.8 µm in wavelength and reveals multiple water absorption bands, the potassium resonance doublet, as well as signatures of clouds. The precision and broad wavelength coverage of NIRISS-SOSS allows us to break model degeneracies between cloud properties and the atmospheric composition of WASP-39 b, favouring a heavy element enhancement ("metallicity") of ~10 – 30× the solar value, a sub-solar carbon-to-oxygen (C/O) ratio, and a solar-to-super-solar potassium-to-oxygen (K/O) ratio. The observations are also best explained by wavelength-dependent, non-gray clouds with inhomogeneous coverage of the planet’s terminator. © 2022, CC BY.

关键词： Water absorption

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Dark Excitons: Dark-Exciton-Mediated Fano Resonance from a Single Gold Nanostructure on Monolayer WS2at Room Temperature (Small 31/2019)

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Small 2019年第31期15卷

作者： Mingsong Wang Zilong Wu Alex Krasnok Tianyi Zhang Mingzu Liu He Liu Leonardo Scarabelli Jie Fang Luis M. Liz-Marzán Mauricio Terrones Andrea Alù Yuebing Zheng Department of Mechanical Engineering Texas Materials Institute The University of Texas at Austin Austin TX 78712 USA Photonics Initiative Advanced Science Research Center Physics Program Graduate Center Department of Electrical Engineering City College of the City University of New York New York NY 10031 USA Department of Materials Science and Engineering Department of Physics Department of Chemistry Center for 2-Dimensional and Layered Materials The Pennsylvania State University University Park PA 16802 USA Department of Chemistry and Biochemistry California NanoSystems Institute University of California Los Angeles Los Angeles CA 90095 USA Bionanoplasmonics Laboratory CIC biomaGUNE Paseo de Miramón 182 20014 Donostia-San Sebastián Spain Ikerbasque Basque Foundation for Science 48013 Bilbao Spain Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine CIBER-BBN 20014 Donostia-San Sebastián Spain

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Using pulsar's braking indices to estimate changes in their moments of inertia with age-related considerations

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Journal of physics: Conference Series 2019年第1期1291卷

作者： H O Oliveira N S Magalhaes R M Marinho G A Carvalho C Frajuca Graduate Program in Physics Technological Institute of Aeronautics Praça Marechal Eduardo Gomes 50 Sao Jose dos Campos SP 12228-900 Brazil Federal University of Sao Paulo Department of Physics Rua Sao Nicolau 210 Diadema SP 09913-030 Brazil Dipartimento di Fisica and ICRA Sapienza Università di Roma P.le Aldo Moro 5 I–00185 Rome Italy ICRANet P.zza della Repubblica 10 I–65122 Pescara Italy Federal Institute of Education Science and Technology of Sao Paulo R. Pedro Vicente 625 Sao Paulo SP 01109-010 Brazil

Pulsars are modeled as neutron stars originated from the collapse of a progenitor one. In the canonical model they are described by spherical magnetized dipoles that rotate with the magnetic axis usually misaligned relative to the rotation axis, and such misalignment would explain the observation of radiation emitted in pulses in a certain direction rendering the typical observational characteristic of this kind of star. The frequency of such pulses decays with time and it can be quantified by the braking index (n). In the canonical model n = 3 for all pulsars but observational data show that n [negationslash] = 3. In this work we present a model for the understanding of the frequency decay of the rotation of a pulsar adapting the canonical one. We consider the pulsar a star that rotates in vacuum and has a strong magnetic field but, in contrast to the canonical model, we assume that its moment of inertia changes in time due to a uniform variation of a displacement parameter in time. We found that the old pulsars that present high values of the braking index tend to present smaller internal displacements of mass, in particular the superfluid neutron matter in the core. We relate this trend to neutron vortices' creep in rotating superfluids, indicating a possible reason for this coincidence.

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MAGIC observations provide compelling evidence of the hadronic multi-TeV emission from the putative PeVatron SNR G106.3+2.7

arXiv

引用

arXiv 2022年

作者： Abe, H. Abe, S. Acciari, V.A. Agudo, I. Aniello, T. Ansoldi, S. Antonelli, L.A. Engels, A. Arbet Arcaro, C. Artero, M. Asano, K. Baack, D. Babić, A. Baquero, A. de Almeida, U. Barres Barrio, J.A. Batković, I. Baxter, J. González, J. Becerra Bednarek, W. Bernardini, E. Bernardos, M. Berti, A. Besenrieder, J. Bhattacharyya, W. Bigongiari, C. Biland, A. Blanch, O. Bonnoli, G. Bošnjak, Ž. Burelli, I. Busetto, G. Carosi, R. Carretero-Castrillo, M. Castro-Tirado, A.J. Ceribella, G. Chai, Y. Chilingarian, A. Cikota, S. Colombo, E. Contreras, J.L. Cortina, J. Covino, S. D’Amico, G. D’Elia, V. Da Vela, P. Dazzi, F. De Angelis, A. De Lotto, B. Popolo, A. Del Delfino, M. Delgado, J. Mendez, C. Delgado Depaoli, D. Pierro, F. Di Venere, L. Di Do Souto Espiñeira, E. Prester, D. Dominis Donini, A. Dorner, D. Doro, M. Elsaesser, D. Emery, G. Escudero, J. Ramazani, V. Fallah Fariña, L. Fattorini, A. Font, L. Fruck, C. Fukami, S. Fukazawa, Y. López, R.J. García Garczarczyk, M. Gasparyan, S. Gaug, M. Paiva, J.G. Giesbrecht Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. Grau, R. Green, D. Green, J.G. Hadasch, D. Hahn, A. Hassan, T. Heckmann, L. Herrera, J. Hrupec, D. Hütten, M. Imazawa, R. Inada, T. Iotov, R. Ishio, K. Martínez, I. Jiménez Jormanainen, J. Kerszberg, D. Kobayashi, Y. Kubo, H. Kushida, J. Lamastra, A. Lelas, D. Leone, F. Lindfors, E. Linhoff, L. Lombardi, S. Longo, F. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Lorini, A. Lyard, E. de Oliveira Fraga, B. Machado Majumdar, P. Makariev, M. Maneva, G. Mang, N. Manganaro, M. Mangano, S. Mannheim, K. Mariotti, M. Martínez, M. Aguilar, A. Mas Mazin, D. Menchiari, S. Mender, S. Mićanović, S. Miceli, D. Miener, T. Miranda, J.M. Mirzoyan, R. Molina, E. Mondal, H.A. Moralejo, A. Morcuende, D. Moreno, V. Nakamori, T. Nanci, C. Nava, L. Neustroev, V. Rosillo, M. Nievas Nigro, C. Nilsson, K. Nishijima, K. Ekoume, T. Njoh Noda, K. Nozaki, S. Ohtani, Y. Oka, T. Okumura, A. The University of Tokyo Chiba Kashiwa277-8582 Japan Instituto de Astrofísica de Canarias Dpto. de Astrofísica Universidad de La Laguna La Laguna TenerifeE-38200 Spain Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n Granada18008 Spain RomeI-00136 Italy Università di Udine INFN Trieste UdineI-33100 Italy Max-Planck-Institut für Physik MünchenD-80805 Germany Università di Padova INFN PadovaI-35131 Italy Bellaterra BarcelonaE-08193 Spain Technische Universität Dortmund DortmundD-44221 Germany Zagreb10000 Croatia IPARCOS Institute EMFTEL Department Universidad Complutense de Madrid MadridE-28040 Spain URCA RJ Rio de Janeiro22290-180 Brazil University of Lodz Faculty of Physics and Applied Informatics Department of Astrophysics Lodz90-236 Poland ZeuthenD-15738 Germany ETH Zürich ZürichCH-8093 Switzerland Università di Pisa INFN Pisa PisaI-56126 Italy Universitat de Barcelona ICCUB IEEC-UB BarcelonaE-08028 Spain Armenian MAGIC Group A. Alikhanyan National Science Laboratory Yerevan0036 Armenia Centro de Investigaciones Energéticas Medioambientales y Tecnológicas MadridE-28040 Spain Department for Physics and Technology University of Bergen Norway INFN MAGIC Group INFN Sezione di Catania Dipartimento di Fisica e Astronomia University of Catania CataniaI-95123 Italy INFN MAGIC Group INFN Sezione di Torino Università degli Studi di Torino TorinoI-10125 Italy INFN MAGIC Group INFN Sezione di Bari Dipartimento Interateneo di Fisica dell’Università e del Politecnico di Bari BariI-70125 Italy Croatian MAGIC Group University of Rijeka Faculty of Physics Rijeka51000 Croatia Universität Würzburg WürzburgD-97074 Germany University of Geneva Chemin d’Ecogia 16 VersoixCH-1290 Switzerland Finnish MAGIC Group Finnish Centre for Astronomy with ESO University of Turku TurkuFI-20014 Finland Departament de Física CERES-IEEC Universitat Autònoma de Barcelona BellaterraE-08193 Spain Japanese MAG

Context. Certain types of Supernova remnants (SNRs) in our Galaxy are assumed to be PeVatrons, capable of accelerating cosmic rays (CRs) to ∼ PeV energies. However, conclusive observational evidence for this has not yet been found. The SNR G106.3+2.7, detected at 1–100 TeV energies by different γ-ray facilities, is one of the most promising PeVatron candidates. This SNR has a cometary shape which can be divided into a head and a tail region with different physical conditions. However, it is not identified in which region the 100 TeV emission is produced due to the limited position accuracy and/or angular resolution of existing observational data. Additionally, it remains unclear whether the origin of the γ-ray emission is leptonic or hadronic. Aims. With the better angular resolution provided by these new MAGIC data compared to earlier γ-ray datasets, we aim to reveal the acceleration site of PeV particles and the emission mechanism by resolving the SNR G106.3+2.7 with 0.1◦ resolution at TeV energies. Methods. We observed the SNR G106.3+2.7 using the MAGIC telescopes for 121.7 hours in total after quality cuts, between May 2017 and August 2019. The analysis energy threshold is ∼ 0.2 TeV, and the angular resolution is 0.07–0.1◦. The γ-ray spectra of different parts of the emission are examined, benefiting from the unprecedented statistics and angular resolution at these energies provided by our new data. The measurements at other wavelengths such as radio, X-rays, GeV γ-rays and 10 TeV γ-rays are also used to model the emission mechanism precisely. Results. We detected extended γ-ray emission spatially coincident with the radio continuum emission at the head and tail of SNR G106.3+2.7. The fact that we detected a significant γ-ray emission with energies above 6.0 TeV from the tail region only suggests that the emissions above 10 TeV, detected with air shower experiments (Milagro, HAWC, Tibet ASγ and LHAASO), are emitted only from the SNR tail. Under this assumption,

关键词： Gamma rays

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Environmental effects on AGN activity via extinction-free mid-infrared census

arXiv

引用

arXiv 2021年

作者： Santos, Daryl Joe D. Goto, Tomotsugu Kim, Seong Jin Wang, Ting-Wen Ho, Simon C.-C. Hashimoto, Tetsuya Huang, Ting-Chi Lu, Ting-Yi On, Alvina Y.L. Wong, Yi-Hang Valerie Hsiao, Tiger Yu-Yang Pollo, Agnieszka Malkan, Matthew A. Miyaji, Takamitsu Toba, Yoshiki Kilerci-Eser, Ece Malek, Katarzyna Hwang, Ho Seong Jeong, Woong-Seob Shim, Hyunjin Pearson, Chris Poliszczuk, Artem Chen, Bo Han Institute of Astronomy National Tsing Hua University No. 101 Section 2 Kuang-Fu Road Hsinchu City30013 Taiwan National Tsing Hua University 101 Section 2. Kuang-Fu Road Hsinchu30013 Taiwan Department of Physics National Chung Hsing University 145 Xingda Rd. South Dist. Taichung40227 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 Mullard Space Science Laboratory University College London Holmbury St. Mary Surrey DorkingRH5 6NT United Kingdom National Centre for Nuclear Research ul. Pasteura 7 Warsaw02-093 Poland Astronomical Observatory of the Jagiellonian University ul. Orla 171 Cracow30-244 Poland Department of Physics and Astronomy UCLA 475 Portola Plaza Los AngelesCA90095-1547 United States Instituto de Astronomía Universidad Nacional Autónoma de México AP 106 Ensenada22860 Mexico Department of Astronomy Kyoto University Kitashirakawa-Oiwake-cho Sakyo-ku Kyoto606-8502 Japan Academia Sinica Institute of Astronomy and Astrophysics 11F of Astronomy-Mathematics Building AS/NTU No.1 Section 4 Roosevelt Road Taipei10617 Taiwan Research Center for Space and Cosmic Evolution Ehime University 2-5 Bunkyo-cho Ehime Matsuyama790-8577 Japan Sabancı University Faculty of Engineering and Natural Sciences Istanbul34956 Turkey Aix Marseille Univ. CNRS CNES LAM Marseille France Astronomy Program Department of Physics and Astronomy Seoul National University 1 Gwanak-ro Seoul Gwanak-gu08826 Korea Republic of SNU Astronomy Research Center Seoul National University 1 Gwanak-ro Seoul Gwanak-gu08826 Korea Republic of Korea Astronomy and Space Science Institute 776 Daedeokdae-ro Daejeon Yuseong-gu34055 Korea Republic of Korea University of Science and Technology 217 Gajeon

How does the environment affect active galactic nucleus (AGN) activity? We investigated this question in an extinction-free way, by selecting 1120 infrared galaxies in the AKARI North Ecliptic Pole Wide field at redshift z ≤ 1.2. A unique feature of the AKARI satellite is its continuous 9-band infrared (IR) filter coverage, providing us with an unprecedentedly large sample of IR spectral energy distributions (SEDs) of galaxies. By taking advantage of this, for the first time, we explored the AGN activity derived from SED modelling as a function of redshift, luminosity, and environment. We quantified AGN activity in two ways: AGN contribution fraction (ratio of AGN luminosity to the total IR luminosity), and AGN number fraction (ratio of number of AGNs to the total galaxy sample). We found that galaxy environment (normalised local density) does not greatly affect either definitions of AGN activity of our IRG/LIRG samples (log LTIR ≤ 12). However, we found a different behavior for ULIRGs (log LTIR > 12). At our highest redshift bin (0.7 . z . 1.2), AGN activity increases with denser environments, but at the intermediate redshift bin (0.3 . z . 0.7), the opposite is observed. These results may hint at a different physical mechanism for ULIRGs. The trends are not statistically significant (p ≥ 0.060 at the intermediate redshift bin, and p ≥ 0.139 at the highest redshift bin). Possible different behavior of ULIRGs is a key direction to explore further with future space missions (e.g., JWST, Euclid, SPHEREx). © 2021, CC BY.

关键词： Galaxies

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