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A-STEP: The AstroPix Sounding Rocket technology Demonstration Payload

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arXiv 2024年

作者： Violette, Daniel P. Steinhebel, Amanda Roy, Abhradeep Boggs, Ryan Caputo, Regina Durachka, David Fukazawa, Yasushi Hashizume, Masaki Hesh, Scott Jadhav, Manoj Kierans, Carolyn Kumar, Kavic Kushima, Shin Leys, Richard Metcalfe, Jessica Metzler, Zachary Nakano, Norito Peric, Ivan Perkins, Jeremy Seo, Lindsey Taylor Shin, K.-W. Striebig, Nicolas Suda, Yusuke Tajima, Hiroyasu NASA Goddard Space Flight Center GreenbeltMD United States United States Physics Program Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima Japan NASA Wallops Flight Facility Wallops IslandVA United States Argonne National Laboratory LemontIL United States Department of Physics University of Maryland College ParkMD United States Institute for Space–Earth Environmental Research Nagoya University Aichi Japan ASIC and Detector Laboratory Karlsruhe Institute of Technology Karlsruhe Germany Institute for Particle Physics University of California Santa CruzCA United States

A next-generation medium-energy (100 keV to 100 MeV) gamma-ray observatory will greatly enhance the identification and characterization of multimessenger sources in the coming decade. Coupling gamma-ray spectroscopy, imaging, and polarization to neutrino and gravitational wave detections will develop our understanding of various astrophysical phenomena including compact object mergers, supernovae remnants, active galactic nuclei and gamma-ray bursts. An observatory operating in the MeV energy regime requires technologies that are capable of measuring Compton scattered photons and photons interacting via pair production. AstroPix is a monolithic high voltage CMOS active pixel sensor which enables future gamma-ray telescopes in this energy range. AstroPix’s design is iterating towards low-power (∼1.5 mW/cm2), high spatial (500 µm pixel pitch) and spectral (2 building block of future large area AstroPix instruments, such as ComPair-2 and AMEGO-X. This payload will be the first demonstration of AstroPix detectors operated in a space environment and will demonstrate the technology’s readiness for future astrophysical and nuclear physics applications. In this work, we overview the design and state of development of the A-STEP payload. Copyright © 2024, The Authors. All rights reserved.

关键词： Photons

The Japanese Vision for the Black Hole Explorer Mission

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arXiv 2024年

作者： Akiyama, Kazunori Niinuma, Kotaro Hada, Kazuhiro Doi, Akihiro Hagiwara, Yoshiaki Higuchi, Aya E. Honma, Mareki Kawashima, Tomohisa Kolev, Dimitar Koyama, Shoko Masui, Sho Ohsuga, Ken Sano, Hidetoshi Takami, Hideki Tsunetoe, Yuh Uzawa, Yoshinori Akahori, Takuya Akiyama, Yuto Galison, Peter Hayashi, Takayuki J. Hirota, Tomoya Inoue, Makoto Iwata, Yuhei Johnson, Michael D. Kino, Motoki Kofuji, Yutaro Mizuno, Yosuke Moriyama, Kotaro Nagai, Hiroshi Nakamura, Kenta Notsu, Shota Ono, Fumie Oya, Yoko Oyama, Tomoaki Rana, Hannah Saida, Hiromi Saito, Ryo Saito, Yoshihiko Sasada, Mahito Sawada-Satoh, Satoko Takahashi, Mikiya M. Takamura, Mieko Tong, Edward Tsuji, Hiroyuki Yoshioka, Shogo Watanabe, Yoshimasa Massachusetts Institute of Technology Haystack Observatory WestfordMA01886 United States Mizusawa VLBI Observatory National Astronomical Observatory of Japan Iwate023-0861 Japan Black Hole Initiative Harvard University CambridgeMA02138 United States Graduate School of Sciences and Technology for Innovation Yamaguchi University Yamaguchi753-8512 Japan The Graduate School of Science Nagoya City University Aichi467-0001 Japan Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Kanagawa252-5210 Japan Department of Space and Astronautical Science The Graduate University for Advanced Studies SOKENDAI Kanagawa229-8510 Japan Natural Science Laboratory Toyo University Tokyo112-8606 Japan Division of Science School of Science and Engineering Tokyo Denki University Saitama350-0394 Japan Department of Astronomy Graduate School of Science The University of Tokyo Tokyo113-0033 Japan Institute for Cosmic Ray Research The University of Tokyo Chiba277-8582 Japan Space Communication Systems Laboratory Wireless Networks Research Center National Institute of Information and Communications Technology Tokyo184-8795 Japan Graduate School of Science and Technology Niigata University Niigata950-2181 Japan Advanced Technology Center National Astronomical Observatory of Japan Tokyo181-8588 Japan Center for Computational Sciences University of Tsukuba Ibaraki305-8577 Japan Faculty of Engineering Gifu University Gifu501-1193 Japan Harvard University CambridgeMA02138 United States Azabu Junior and Senior High School Tokyo106-0046 Japan Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI Tokyo181-8588 Japan Institute of Astronomy and Astrophysics Academia Sinica Taipei10617 Taiwan Center for Astrophysics Harvard & Smithsonian CambridgeMA02138 United States Kogakuin University of Technology & Engineering Academic Support Center 2665-1 Nakano Hachioji Tokyo192-0015 Japan Tsung-Dao Lee Institut

The Black Hole Explorer (BHEX) is a next-generation space very long baseline interferometry (VLBI) mission concept that will extend the ground-based millimeter/submillimeter arrays into space. The mission, closely aligned with the science priorities of the Japanese VLBI community, involves an active engagement of this community in the development of the mission, resulting in the formation of the Black Hole Explorer Japan Consortium. Here we present the current Japanese vision for the mission, ranging from scientific objectives to instrumentation. The Consortium anticipates a wide range of scientific investigations, from diverse black hole physics and astrophysics studied through the primary VLBI mode, to the molecular universe explored via a potential single-dish observation mode in the previously unexplored 50-70 GHz band that would make BHEX the highest-sensitivity explorer ever of molecular oxygen. A potential major contribution for the onboard instrument involves supplying essential elements for its high-sensitivity dual-band receiving system, which includes a broadband 300 GHz SIS mixer and a space-certified multi-stage 4.5K cryocooler akin to those used in the Hitomi and XRISM satellites by the Japan Aerospace Exploration Agency. Additionally, the Consortium explores enhancing and supporting BHEX operations through the use of millimeter/submillimeter facilities developed by the National Astronomical Observatory of Japan, coupled with a network of laser communication stations operated by the National Institute of Information and Communication technology. Copyright © 2024, The Authors. All rights reserved.

关键词： Radio astronomy

Merger and Postmerger of Binary Neutron Stars with a Quark-Hadron Crossover Equation of State

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Physical Review Letters 2022年第18期129卷 181101-181101页

作者： Yong-Jia Huang Luca Baiotti Toru Kojo Kentaro Takami Hajime Sotani Hajime Togashi Tetsuo Hatsuda Shigehiro Nagataki Yi-Zhong Fan Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Science Nanjing 210023 China School of Astronomy and Space Sciences University of Science and Technology of China Hefei Anhui 230026 China RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) RIKEN Wako 351-0198 Japan International College and Graduate School of Science Osaka University 1-2 Machikaneyama-cho Toyonaka Osaka 560-0043 Japan Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics Central China Normal University Wuhan 430079 China Department of Physics Tohoku University Sendai 980-8578 Japan Kobe City College of Technology 651-2194 Kobe Japan RIKEN Astrophysical Big Bang Laboratory (ABBL) Cluster for Pioneering Research Wako Saitama 351-0198 Japan

Fully general-relativistic binary-neutron-star (BNS) merger simulations with quark-hadron crossover (QHC) equations of state (EOS) are studied for the first time. In contrast to EOS with purely hadronic matter or with a first-order quark-hadron phase transition (1PT), in the transition region QHC EOS show a peak in sound speed and thus a stiffening. We study the effects of such stiffening in the merger and postmerger gravitational (GW) signals. Through simulations in the binary-mass range 2.5

关键词： Gravitational waves Nuclear matter in neutron stars Binary stars Neutron stars & pulsars Numerical relativity Numerical simulations in gravitation & astrophysics

Optical Variability of Blazars in the Tomo-e Gozen Northern Sky Transient Survey

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arXiv 2024年

作者： Zhang, TianFang Doi, Mamoru Kokubo, Mitsuru Sako, Shigeyuki Ohsawa, Ryou Tominaga, Nozomu Tanaka, Masaomi Fukazawa, Yasushi Takahashi, Hidenori Arima, Noriaki Kobayashi, Naoto Arimatsu, Ko Okumura, Shin-Ichiro Kondo, Sohei Kasuga, Toshihiro Mori, Yuki Niino, Yuu Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongō Bunkyo City Tokyo113-8654 Japan Institute of Astronomy Graduate School of Science The University of Tokyo 2-21-1 Osawa Mitaka Tokyo181-0015 Japan National Astronomical Observatory of Japan National Institutes of Natural Science 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Research Center for the Early Universe School of Science The University of Tokyo Bldg. No.4 7-3-1 Hongō Bunkyo City Tokyo113-0033 Japan UTokyo Organization for Planetary Space Science The University of Tokyo 7-3-1 Hongō Bunkyo City Tokyo113-8654 Japan Collaborative Research Organization for Space Science and Technology The University of Tokyo 7-3-1 Hongō Bunkyo City Tokyo113-8654 Japan Astronomical Science Program Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Department of Physics Faculty of Science and Engineering Konan University 8-9-1 Okamoto Hyogo Kobe658-8501 Japan Astronomical Institute Tohoku University Aoba Sendai980-8578 Japan Division for the Establishment of Frontier Sciences Organization for Advanced Studies Tohoku University Sendai980-8577 Japan Department of Physics Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima739-8526 Japan Kiso Observatory Institute of Astronomy Graduate School of Science The University of Tokyo Mitake 10762-30 Kiso-machi Kiso-gun Nagano397-0101 Japan Hakubi Center Astronomical Observatory Graduate School of Science Kyoto University Kitashirakawa-Oiwakecho Sakyo-ku Kyoto606-8502 Japan Japan Spaceguard Association Bisei Spaceguard Center 1716-3 Okura Bisei Ibara Okayama714-1411 Japan

We studied the optical variability of 241 BL Lacs and 83 flat-spectrum radio quasars (FSRQ) from the 4LAC catalog using data from the Tomo-e Gozen Northern Sky Transient Survey, with ∼ 50 epochs per blazar on average. We excluded blazars whose optical variability may be underestimated due to the influence of their host galaxy, based on their optical luminosity (LO). FSRQs with γ-ray photon index greater than 2.6 exhibit very low optical variability, and their distribution of standard deviation of repeated photometry is significantly different from that of the other FSRQs (KS test P value equal to 5 × 10−6 ). Among a sample of blazars at any particular cosmological epoch, those with lower γ-ray luminosity (Lγ) tend to have lower optical variability, and those FSRQs with γ-ray photon index greater than 2.6 tend to have low Lγ. We also measured the structure function of optical variability and found that the amplitude of the structure function for FSRQs is higher than previously measured and higher than that of BL Lacs at multiple time lags. Additionally, the amplitude of the structure function of FSRQs with high γ-ray photon index is significantly lower than that of FSRQs with low γ-ray photon index. The structure function of FSRQs of high γ-ray photon index shows a characteristic timescale of more than 10 days, which may be the variability timescale of the accretion disk. In summary, we infer that the optical component of FSRQs with high γ-ray photon index may be dominated by the accretion disk. © 2024, CC BY.

关键词： Gamma rays

Transition probabilities of near-infrared Ce III lines from stellar spectra: applications to kilonovae

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arXiv 2023年

作者： Domoto, Nanae Lee, Jae-Joon Tanaka, Masaomi Lee, Ho-Gyu Aoki, Wako Ishigaki, Miho N. Wanajo, Shinya Kato, Daiji Hotokezaka, Kenta Astronomical Institute Tohoku University Aoba Sendai980-8578 Japan Korea Astronomy and Space Science Institute 776 Daedeok-daero Yuseong-gu Daejeon34055 Korea Republic of Division for the Establishment of Frontier Sciences Organization for Advanced Studies Tohoku University Sendai980-8577 Japan Space Policy Research Center Science and Technology Policy Institute 370 Sicheong-daero Sejong30147 Korea Republic of National Astronomical Observatory 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 Am Mühlenberg 1 Potsdam-GolmD-14476 Germany RIKEN Saitama Wako351-0198 Japan National Institute for Fusion Science 322-6 Oroshi-cho Toki509-5292 Japan Interdisciplinary Graduate School of Engineering Sciences Kyushu University Fukuoka Kasuga816-8580 Japan Research Center for the Early Universe Graduate School of Science University of Tokyo Tokyo Bunkyo113-0033 Japan UTIAS The University of Tokyo Chiba Kashiwa277-8583 Japan

Kilonova spectra provide us with information of r-process nucleosynthesis in neutron star mergers. However, it is still challenging to identify individual elements in the spectra mainly due to lack of experimentally accurate atomic data for heavy elements in the near-infrared wavelengths. Recently, Domoto et al. (2022) proposed the absorption features around 14500 Å in the observed spectra of GW170817/AT2017gfo as Ce III lines. But they used theoretical transition probabilities (gf-values) whose accuracy is uncertain. In this paper, we derive the astrophysical gf-values of the three Ce III lines, aiming at verification of this identification. We model high resolution H-band spectra of four F-type supergiants showing the clear Ce III absorption features by assuming stellar parameters derived from optical spectra in literatures. We also test the validity of the derived astrophysical gf-values by estimating Ce III abundances in Ap stars. We find that the derived astrophysical gf-values of the Ce III lines are systematically lower by about 0.25 dex than those used in previous work of kilonovae, while they are still compatible within the uncertainty range. By performing radiative transfer simulations of kilonovae with the derived gf-values, we find that the identification of Ce III as a source of the absorption features in the observed kilonova spectra still stands, even considering the uncertainties in the astrophysical gf-values. This supports identification of Ce in the spectra of GW170817/AT2017gfo. © 2023, CC BY.

关键词： Stars

Galaxy clusters at z ∼ 1 imaged by ALMA with the Sunyaev–Zel’dovich effect

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Publications of the Astronomical Society of Japan 2023年第2期75卷 311-337页

作者： Kitayama, Tetsu Ueda, Shutaro Okabe, Nobuhiro Akahori, Takuya Hilton, Matt Hughes, John P. Ichinohe, Yuto Kohno, Kotaro Komatsu, Eiichiro Lin, Yen-Ting Miyatake, Hironao Oguri, Masamune Sifón, Cristóbal Takakuwa, Shigehisa Takizawa, Motokazu Tsutsumi, Takahiro van Marrewijk, Joshiwa Wollack, Edward J. Department of Physics Toho University 2-2-1 Miyama Chiba Funabashi274-8510 Japan No. 1 Section 4 Roosevelt Road Taipei10617 Taiwan Institute of Astronomy National Tsing Hua University Hsinchu30013 Taiwan Department of Physics Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Astrophysical Science Center Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Core Research for Energetic Universe Department of Physics Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Physics Program Graduate School of Advanced Science and Engineering Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Mizusawa VLBI observatory National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Operation Division SKA Observatory Jodrell Bank Lower Withington MacclesfieldSK11 9DL United Kingdom Astrophysics Research Centre University of KwaZulu-Natal Westville Campus Durban4041 South Africa School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Westville Campus Durban4041 South Africa Wits Centre for Astrophysics School of Physics University of the Witwatersrand Private Bag 3 Johannesburg2050 South Africa Department of Physics and Astronomy Rutgers The State University of New Jersey PiscatawayNJ08854-8019 United States Department of Physics Rikkyo University 3-34-1 Nishi-Ikebukuro Toshima-ku Tokyo171-8501 Japan Institute of Astronomy School of Science The University of Tokyo 2-21-1 Osawa Mitaka Tokyo181-0015 Japan Research Center for the Early Universe School of Science The University of Tokyo 7-3-1 Hongo Bunkyo Tokyo113-0033 Japan Max-Planck-Institut für Astrophysik Karl-Schwarzschild Str. 1 GarchingD-85741 Germany The University of Tokyo Institutes for Advanced Study The University of Tokyo 5-1-5 Kashiwanoha Chiba Kashiwa277-8583 Japan Nagoya University Furo-cho Chikusa-

We present high angular resolution measurements of the thermal Sunyaev–Zel’dovich effect (SZE) toward two galaxy clusters, RCS J2319+0038 at z = 0.9 and HSC J0947−0119 at z = 1.1, by the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3. They are supplemented with available Chandra X-ray data, optical data taken by Hyper Suprime-Cam on Subaru, and millimeter-wave SZE data from the Atacama Cosmology Telescope. Taking into account departures from spherical symmetry, we have reconstructed non-parametrically the inner pressure profile of two clusters as well as electron temperature and density profiles for RCS J2319+0038. This is one of the first such measurements for an individual cluster at z 0.9. We find that the inner pressure profile of both clusters is much shallower than that of local cool-core clusters. Our results consistently suggest that RCS J2319+0038 hosts a weak cool core, where radiative cooling is less significant than in local cool cores. On the other hand, HSC J0947−0119 exhibits an even shallower pressure profile than RCS J2319+0038 and is more likely to be a non-cool-core cluster. The SZE centroid position is offset by more than 140 h−170 kpc from the peaks of galaxy distribution in HSC J0947−0119, suggesting a stronger influence of mergers in this cluster. We conclude that these distant clusters are at a very early stage of developing the cool cores typically found in clusters at lower redshifts. © The Author(s) 2023. Published by Oxford University Press on behalf of the Astronomical Society of Japan.

关键词： Millimeter waves

The ALMA-QUARKS Survey.Ⅰ.Survey Description and Data Reduction

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Research in Astronomy and Astrophysics 2024年第2期24卷 104-124页

作者：刘训川 Tie Liu Lei Zhu Guido Garay Hong-Li Liu Paul Goldsmith Neal Evans Kee-Tae Kim Sheng-Yuan Liu Fengwei Xu Xing Lu Anandmayee Tej Xiaofeng Mai Leonardo Bronfman Shanghuo Li Diego Mardones Amelia Stutz Ken'ichi Tatematsu Ke Wang Qizhou Zhang Sheng-Li Qin Jianwen Zhou Qiuyi Luo Siju Zhang Yu Cheng Jinhua He Qilao Gu Ziyang Li Zhenying Zhang Suinan Zhang Anindya Saha Lokesh Dewangan Patricio Sanhueza Zhiqiang Shen Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Departamento de Astronomía Universidad de ChileLas Condes7591245 SantiagoChile School of Physics and Astronomy Yunnan UniversityKunming 650091China Jet Propulsion Laboratory California Institute of Technology4800 Oak Grove DrivePasadena CA 91109USA Department of Astronomy The University of Texas at AustinTX 78712-1205USA Korea Astronomy and Space Science Institute 776 Daedeokdae-roYuseong-guDaejeon 34055Republic of Korea Institute of Astronomy and Astrophysics Academia SinicaRoosevelt RoadTaipei 10617China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Department of Astronomy School of PhysicsPeking UniversityBeijing 100871China Indian Institute of Space Science and Technology Thiruvananthapuram 695547KeralaIndia Max Planck Institute for Astronomy Königstuhl 17D-69117 HeidelbergGermany Departamento de Astronomía Universidad de ConcepciónCasilla 160-CConcepciónChile Nobeyama Radio Observatory National Astronomical Observatory of JapanNational Institutes of Natural Sciences462-2 NobeyamaMinamimakiMinamisakuNagano 384-1305Japan Center for Astrophysics∣Harvard&Smithsonian 60 Garden StreetCambridgeMA 02138USA Max-Planck-Institut für Radioastronomie Auf dem Hügel 69D-53125 BonnGermany School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China National Astronomical Observatory of Japan 2-21-1 OsawaMitakaTokyo181-8588Japan Yunnan Observatories Chinese Academy of SciencesKunming 650216China Physical Research Laboratory NavrangpuraAhmedabad-380009India Astronomical Science Program The Graduate University for Advanced StudiesSOKENDAI2-21-1 OsawaMitakaTokyo 181-8588Japan University of Science and Technology Korea(UST)217 Gajeong-roYuseong-guDaejeon 34113Republic o

This paper presents an overview of the QUARKS survey,which stands for Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures."The QUARKS survey is observing139 massive clumps covered by 156 pointings at Atacama Large Millimeter/submillimeter Array(ALMA)Band 6(λ~1.3 mm).In conjunction with data obtained from the ALMA-ATOMS survey at Band 3(λ~3 mm),QUARKS aims to carry out an unbiased statistical investigation of massive star formation process within protoclusters down to a scale of 1000 *** overview paper describes the observations and data reduction of the QUARKS survey,and gives a first look at an exemplar source,the mini-starburst Sgr B2(M).The wide-b and width(7.5 GHz)and high-angular-resolution(~0."3)observations of the QUARKS survey allow for the resolution of much more compact cores than those could be done by the ATOMS survey,and to detect previously unrevealed fainter filamentary *** spectral windows cover transitions of species including CO,SO,N_(2)D^(+),SiO,H_(30)α,H_(2)CO,CH_(3)CN,and many other complex organic molecules,tracing gas components with different temperatures and spatial *** aims to deepen our understanding of several scientific topics of massive star formation,such as the mass transport within protoclusters by(hub-)filamentary structures,the existence of massive starless cores,the physical and chemical properties of dense cores within protoclusters,and the feedback from already formed high-mass young protostars.

关键词： stars formation-stars kinematics and dynamics-ISM clouds-ISM molecules

Development of advanced photon calibrator for Kamioka gravitational wave detector (KAGRA)

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arXiv 2023年

作者： Inoue, Y. Hsieh, B.H. Chen, K.H. Chu, Y.K. Ito, K. Kozakai, C. Shishido, T. Tomigami, Y. Akutsu, T. Haino, S. Izumi, K. Kajita, T. Kanda, N. Lin, C.S. Lin, F.K. Moriwaki, Y. Ogaki, W. Pang, H.F. Sawada, T. Tomaru, T. Suzuki, T. Tsuchida, S. Ushiba, T. Washimi, T. Yamamoto, T. Yokozawa, T. Department of Physics National Central University Taoyuan Zhongli32001 Taiwan Center for High Energy and High Field Physics National Central University Taoyuan Zhongli32001 Taiwan Institute of Physics Academia Sinica Taipei11529 Taiwan High Energy Accelerator Research Organization Ibaraki305-0801 Japan Institute for Cosmic Ray Research The University of Tokyo Chiba277-8582 Japan Molecular Sciences and Technology Taiwan International Graduate Program Academia Sinica National Central University Taipei Taiwan Institute of Atomic and Molecular Science Academia Sinica Taipei10617 Taiwan Department of Physics University of Toyama Toyama930-8555 Japan Kanagawa240-0115 Japan Department of Physics Graduate School of Science Osaka City University Osaka558-8585 Japan Tokyo181-8588 Japan JAXA Institute of Space and Astronautical Science Chuo-ku Kanagawa Sagamihara City252-0222 Japan Department of Physics Graduate School of Science Osaka Metropolitan University Osaka558-8585 Japan Osaka Metropolitan University Osaka558-8585 Japan

The KAGRA cryogenic gravitational-wave observatory has begun joint observation with the worldwide gravitational waves detector network. Precise calibration of the detector response is essential for the parameter estimation of gravitational wave sources. The photon calibrator is the main calibrator in LIGO, Virgo and KAGRA, and we used this calibrator in joint observation 3 on 2020 April with GEO600 in Germany. KAGRA improved the system for joint observation 3 with three unique points: high laser power, power stabilization system, and remote beam position control. KAGRA employs the 20 W laser and divides it into two beams injected on the mirror surface. By using a high-power laser, we can calibrate the response at the kHz region. To control the power of each laser independently, we also installed an optical follower servo for each beam power stabilization. By controlling the optical path of the photon calibrater beam positions with pico-motors, we were able to characterize the rotation response of the detector. We also installed a telephoto camera and QPD to monitor beam position and controlled beam position to optimize mirror response. In this paper, we discussed the statistical error with the result of the relative power noise measurement. We also discussed systematic errors about the power calibration model of photon calibrator and simulation of elastic deformation effect with the finite element analysis. © 2023, CC BY.

关键词： Photons

An ALMA Glimpse of Dense Molecular Filaments Associated with High-mass Protostellar Systems in the Large Magellanic Cloud

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arXiv 2023年

作者： Tokuda, Kazuki Harada, Naoto Tanaka, Kei E.I. Inoue, Tsuyoshi Shimonishi, Takashi Zhang, Yichen Sewilo, Marta Kunitoshi, Yuri Konishi, Ayu Fukui, Yasuo Kawamura, Akiko Onishi, Toshikazu Machida, Masahiro N. Department of Earth and Planetary Sciences Faculty of Science Kyushu University Fukuoka Nishi-ku819-0395 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Department of Earth and Planetary Sciences Tokyo Institute of Technology Meguro Tokyo152-8551 Japan Department of Physics Konan University Okamoto 8-9-1 Kobe Japan Environmental Science Program Faculty of Science Niigata University Ikarashi-ninocho 8050 Nishi-ku Niigata950-2181 Japan Department of Astronomy University of Virginia CharlottesvilleVA22904-4325 United States RIKEN Cluster for Pioneering Research Saitama Wako351-0198 Japan Exoplanets and Stellar Astrophysics Laboratory NASA Goddard Space Flight Center GreenbeltMD20771 United States Department of Astronomy University of Maryland College ParkMD20742 United States Center for Research and Exploration in Space Science and Technology NASA Goddard Space Flight Center GreenbeltMD20771 United States Department of Physics Graduate School of Science Osaka Metropolitan University 1-1 Gakuen-cho Naka-ku Sakai Osaka599-8531 Japan Department of Physics Nagoya University Furo-cho Chikusa-ku Nagoya464-8601 Japan

Recent millimeter/sub-millimeter facilities have revealed the physical properties of filamentary molecular clouds in relation to high-mass star formation. A uniform survey of the nearest, face-on star-forming galaxy, the Large Magellanic Cloud (LMC), complements the Galactic knowledge. We present ALMA survey data with a spatial resolution of ∼0.1 pc in the 0.87 mm continuum and HCO+(4–3) emission toward 30 protostellar objects with luminosities of 104–105.5 L☉ in the LMC. The spatial distributions of the HCO+(4–3) line and thermal dust emission are well correlated, indicating that the line effectively traces dense, filamentary gas with an H2 volume density of 105 cm−3 and a line mass of ∼103–104 M☉ pc−1. Furthermore, we obtain an increase in the velocity linewidths of filamentary clouds, which follows a power-law dependence on their H2 column densities with an exponent of ∼0.5. This trend is consistent with observations toward filamentary clouds in nearby star-forming regions withiin 1 kpc from us and suggests enhanced internal turbulence within the filaments owing to surrounding gas accretion. Among the 30 sources, we find that 14 are associated with hub-filamentary structures, and these complex structures predominantly appear in protostellar luminosities exceeding ∼5 ×104 L☉. The hub-filament systems tend to appear in the latest stages of their natal cloud evolution, often linked to prominent H ii regions and numerous stellar clusters. Our preliminary statistics suggest that the massive filaments accompanied by hub-type complex features may be a necessary intermediate product in forming extremely luminous high-mass stellar systems capable of ultimately dispersing the parent cloud. © 2023, CC BY.

关键词： Clouds