检索结果-内蒙古大学图书馆

The eROSITA Final Equatorial-Depth Survey (eFEDS): A complete census of X-ray properties of Subaru Hyper Suprime-Cam weak lensing shear-selected clusters in the eFEDS footprint

arXiv

引用

arXiv 2021年

作者： Ramos-Ceja, Miriam Elizabeth Oguri, M. Miyazaki, S. Ghirardini, V. Chiu, I. Okabe, N. Liu, A. Schrabback, T. Akino, D. Bahar, Y.E. Bulbul, E. Clerc, N. Comparat, J. Grandis, S. Klein, M. Lin, Y.-T. Merloni, A. Mitsuishi, I. Miyatake, H. More, S. Nandra, K. Nishizawa, A.J. Ota, N. Pacaud, F. Reiprich, T.H. Sanders, J.S. Max Planck Institut für Extraterrestrische Physik Giessenbachstraße 1 GarchingD-85748 Germany Research Center for the Early Universe University of Tokyo Tokyo113-0033 Japan Department of Physics University of Tokyo Tokyo113-0033 Japan University of Tokyo Chiba277-8582 Japan National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Mitaka Tokyo181-8588 Japan Tsung-Dao Lee Institute Key Laboratory for Particle Physics Astrophysics and Cosmology Ministry of Education Shanghai Jiao Tong University Shanghai200240 China Department of Astronomy School of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong University Shanghai200240 China No. 1 Section 4 Roosevelt Road Taipei10617 Taiwan Physics Program Graduate School of Advanced Science and Engineering Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Hiroshima Astrophysical Science Center Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Core Research for Energetic Universe Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Universität Bonn Auf dem Hügel 71 Bonn53121 Germany IRAP Université de Toulouse CNRS UPS CNES Toulouse France Faculty of Physics Ludwig-Maximilians-Universität Scheinerstr. 1 Munich81679 Germany Division of Physics and Astrophysical Science Graduate School of Science Nagoya University Aichi Nagoya464-8602 Japan Nagoya University Nagoya464-8602 Japan Institute for Advanced Research Nagoya University Nagoya464-8601 Japan The Inter University Centre for Astronomy and Astrophysics Ganeshkhind Pune411007 India Department of Physics Nara Women's University Kitauoyanishimachi Nara630-8506 Japan

Context. The eFEDS survey is a proof-of-concept mini-survey designed to demonstrate the survey science capabilities of SRG/eROSITA. It covers an area of 140 deg2 where ∼ 540 galaxy clusters have been detected out to a redshift of 1.3. The eFEDS field is partly embedded in the Hyper Suprime-Cam Subaru Strategic program (HSC-SSP) S19A data release, which covers ∼ 510 deg2, containing approximately 36 million galaxies. This galaxy catalogue has been used to construct a sample of ∼ 180 shear-selected galaxy clusters. The common area to both surveys covers about 90 deg2, making it an ideal region to study galaxy clusters selected in different ways. Aims. The aim of this work is to investigate the effects of selection methods in the galaxy cluster detection by comparing the X-ray selected, eFEDS, and the shear-selected, HSC-SSP S19A, galaxy cluster samples. There are 25 shear-selected clusters in the eFEDS fooprint. Methods. The relation between X-ray bolometric luminosity and weak-lensing mass is investigated (Lbol − M relation), comparing this relation derived from a shear-selected cluster sample to the relation obtained from an X-ray selected sample. Moreover, the dynamical state of the shear-selected clusters is investigated and compared to the X-ray selected sample using X-ray morphological parameters and galaxy distribution. Results. The normalisation of the Lbol − M relation of the X-ray selected and shear-selected samples is consistent within 1σ. Moreover, the dynamical state and merger fraction of the shear-selected clusters is not different from the X-ray selected ones. Four shear-selected clusters are undetected in X-rays. A close inspection reveals that one is the result of projection effects, while the other three have an X-ray flux below the ultimate eROSITA detection limit. Finally, 43% of the shear-selected clusters lie in superclusters. Conclusions. Our results indicate that the scaling relation between X-ray bolometric luminosity and true cluster mass of

关键词： Surveys

来源：评论

学校读者我要写书评

暂无评论

Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy

引用

Astrophysical Journal Letters 2024年第2期967卷 L21-L21页

作者： Kuzuhara, Masayuki Fukui, Akihiko Livingston, John H. Caballero, José A. de Leon, Jerome P. Hirano, Teruyuki Kasagi, Yui Murgas, Felipe Narita, Norio Omiya, Masashi Orell-Miquel, Jaume Palle, Enric Changeat, Quentin Esparza-Borges, Emma Harakawa, Hiroki Hellier, Coel Hori, Yasunori Ikuta, Kai Ishikawa, Hiroyuki Tako Kodama, Takanori Kotani, Takayuki Kudo, Tomoyuki Morales, Juan C. Mori, Mayuko Nagel, Evangelos Parviainen, Hannu Perdelwitz, Volker Reiners, Ansgar Ribas, Ignasi Sanz-Forcada, Jorge Sato, Bun’ei Schweitzer, Andreas Tabernero, Hugo M. Takarada, Takuya Uyama, Taichi Watanabe, Noriharu Zechmeister, Mathias García, Néstor Abreu Aoki, Wako Beichman, Charles Béjar, Víctor J. S. Brandt, Timothy D. Calatayud-Borras, Yéssica Carleo, Ilaria Charbonneau, David Collins, Karen A. Currie, Thayne Doty, John P. Dreizler, Stefan Fernández-Rodríguez, Gareb Fukuda, Izuru Galán, Daniel Geraldía-González, Samuel González-Garcia, Josafat Hayashi, Yuya Hedges, Christina Henning, Thomas Hodapp, Klaus Ikoma, Masahiro Isogai, Keisuke Jacobson, Shane Janson, Markus Jenkins, Jon M. Kagetani, Taiki Kambe, Eiji Kawai, Yugo Kawauchi, Kiyoe Kokubo, Eiichiro Konishi, Mihoko Korth, Judith Krishnamurthy, Vigneshwaran Kurokawa, Takashi Kusakabe, Nobuhiko Kwon, Jungmi Laza-Ramos, Andrés Libotte, Florence Luque, Rafael Madrigal-Aguado, Alberto Matsumoto, Yuji Mawet, Dimitri McElwain, Michael W. Gallardo, Pedro Pablo Meni Morello, Giuseppe Torres, Sara Muñoz Nishikawa, Jun Nugroho, Stevanus K. Ogihara, Masahiro Peláez-Torres, Alberto Rapetti, David Sánchez-Benavente, Manuel Schlecker, Martin Seager, Sara Serabyn, Eugene Serizawa, Takuma Stangret, Monika Takahashi, Aoi Teng, Huan-Yu Tamura, Motohide Terada, Yuka Ueda, Akitoshi Usuda, Tomonori Vanderspek, Roland Vievard, Sébastien Watanabe, David Winn, Joshua N. Zapatero Osorio, Maria Rosa Astrobiology Center NINS 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan National Astronomical Observatory of Japan NINS 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Komaba Institute for Science The University of Tokyo 3-8-1 Komaba Meguro Tokyo 153-8902 Japan Instituto de Astrofísica de Canarias (IAC) La Laguna Tenerife E-38200 Spain Astronomical Science Program Graduate University for Advanced Studies (SOKENDAI) 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Centro de Astrobiología CSIC-INTA Camino Bajo del Castillo s/n Villanueva de la Cañada Madrid E-28692 Spain Department of Multi-Disciplinary Sciences Graduate School of Arts and Sciences The University of Tokyo 3-8-1 Komaba Meguro Tokyo 153-8902 Japan Departamento de Astrofísica Universidad de La Laguna (ULL) La Laguna Tenerife E-38206 Spain European Space Agency (ESA) ESA Office Space Telescope Science Institute (STScI) Baltimore 21218 MD United States Department of Physics and Astronomy University College London Gower Street London WC1E 6BT United Kingdom National Astronomical Observatory of Japan 650 North A‘ohōkū Place Hilo 96720 HI United States Astrophysics Group Keele University Staffordshire ST5 5BG United Kingdom Department of Physics and Astronomy The University of Western Ontario 1151 Richmond Street London N6A 3K7 ON Canada Earth-Life Science Institute (ELSI) Tokyo Institute of Technology 2-12-1-I7E-315 Ookayama Meguro-ku Tokyo 152-8550 Japan Institut de Ciències de l’Espai (ICE CSIC) Campus UAB Can Magrans s/n Bellaterra Barcelona 08193 Spain Institut d’Estudis Espacials de Catalunya (IEEC) c/ Gran Capità 2-4 Barcelona 08034 Spain Institut für Astrophysik und Geophysik Georg-August-Universität Friedrich-Hund-Platz 1 Göttingen 37077 Germany Department of Physics Ariel University Ariel 40700 Israel Department of Earth and Planetary Sciences School of Science Tokyo Institute of Technology 2-12-1 Ookayama Meguro-ku Tokyo 152-8551 Japan Hamburger Sternwarte Goje

Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (P _orb) of 12.76 days. The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous P _orb from TESS data. We confirmed the transit signal and P _orb using ground-based photometry with MuSCAT2 and MuSCAT3, and validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host star is inactive, with an X-ray-to-bolometric luminosity ratio of log L X / L bol ≈ − 5.7 . Joint analysis of the light curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 ± 0.05 R _⊕, a 3σ mass upper limit of 3.9 M _⊕, and an equilibrium temperature of 315 ± 6 K assuming zero albedo. The transmission spectroscopy metric (TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST. © 2024. The Author(s). Published by the American Astronomical Society.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Emergence of nematic paramagnet via quantum order-by-disorder and pseudo-goldstone modes in kitaev magnets

arXiv

引用

arXiv 2020年

作者： Gohlke, Matthias Chern, Li Ern Kee, Hae-Young Kim, Yong Baek Theory of Quantum Matter Unit Okinawa Institute of Science Technology Graduate University Onna-son Okinawa904-0495 Japan Department of Physics University of Toronto TorontoONM5S 1A7 Canada Canadian Institute for Advanced Research Quantum Materials Program TorontoONMSG 1Z8 Canada School of Physics Korea Institute for Advanced Study Seoul130-722 Korea Republic of

The appearance of nontrivial phases in Kitaev materials exposed to an external magnetic field has recently been a subject of intensive studies. Here, we elucidate the relation between the fieldinduced ground states of the classical and quantum spin models proposed for such materials, by using the infinite density matrix renormalization group (iDMRG) and the linear spin wave theory (LSWT). We consider the KΓΓ0 model, where Γ and Γ0 are off-diagonal spin exchanges on top of the dominant Kitaev interaction K. We show that a nematic paramagnet, which breaks the latticerotational symmetry, emerges in the quantum model. This phenomenon can be understood as the effect of quantum order-by-disorder in the frustrated ferromagnet discovered in the corresponding classical model. In addition, various classical ordering patterns with large unit cells are replaced by the nematic paramagnet in the quantum model. We compute the dynamical spin structure factors using a matrix operator based time evolution and compare them with the predictions from LSWT. We point out the existence of a pseudo-Goldstone mode, which results from the lifting of a continuous degeneracy via quantum uctuations. We also discuss these results in the light of inelastic neutron scattering experiments. Copyright © 2020, The Authors. All rights reserved.

关键词： Ground state

来源：评论

学校读者我要写书评

暂无评论

In Situ Derived Sulfated/Sulfonated Carbon Nanogels with Multi-Protective Effects Against Influenza a Virus

SSRN

引用

SSRN 2022年

作者： Lin, Hung-Yun Luo, Ka-Long Mao, Ju-Yi Lin, Chin-Jung Wang, Chen-Yow Panny, Lauren Chen, Shiow-Yi Lin, Shih-Chao Huang, Chih-Ching Harroun, Scott G. Wang, Robert Y.L. Wu, Chang-Jer Center of Excellence for the Oceans National Taiwan Ocean University Keelung202301 Taiwan Department of Food Science National Taiwan Ocean University Keelung202301 Taiwan Department of Bioscience and Biotechnology National Taiwan Ocean University Keelung202301 Taiwan Department of Biomedical Sciences and Pathobiology Virginia-Maryland College of Veterinary Medicine Virginia Polytechnic Institute and State University BlacksburgVA24061 United States Bachelor's Degree Program in Marine Biotechnology College of Life Sciences National Taiwan Ocean University Keelung202301 Taiwan School of Pharmacy College of Pharmacy Kaohsiung Medical University Kaohsiung80708 Taiwan Department of Engineering Physics Polytechnique Montréal MontréalQCH3T 1J4 Canada Division of Microbiology and Immunology Graduate Institute of Biomedical Sciences College of Medicine Chang Gung University Taoyuan33302 Taiwan Department of Health and Nutrition Biotechnology Asia University Taichung41354 Taiwan Graduate Institute of Medicine Kaohsiung Medical University Kaohsiung80708 Taiwan

Pandemic outbreaks of H1N1 infections are frequently reported around the world. Despite the availability of influenza remedies, the high tendency for influenza virus to mutate can lead to the emergence of drug-resistant strains. Additionally, the adverse effects of current anti-flu drugs that can occur for some patients, such as potential psychiatric problems caused by oseltamivir, have led some countries to implement restrictions on the use of these drugs. In response to the urgent demand to explore and design novel antivirals, we have developed potent anti-flu materials derived from alginate (Alg) of seaweeds. Preparation involves a mixture of sodium alginate with ammonia sulfite (AS) in a one-step pyrolytic reaction, which forms carbonized nanogels (CNGs). We have characterized the chemical and physical properties of these Alg@AS CNGs, validated the anti-flu activity in vitro and in vivo, and explored the underlying mechanisms that Alg@AS CNGs could exert. Our results indicate that the Alg@AS CNGs have abundant sulfite/sulfate surface moieties, and that they have high biocompatibility and remarkable viral suppression properties against H1N1. The viral suppression of Alg@AS CNGs was shown to be superior to other sulfated polysaccharides, such as fucoidan, carrageenan, and chondroitin sulfate. The administration of Alg@AS CNGs to H1N1-infected cells and mice resulted in higher cellular viabilities and mouse survival rates, respectively. Improved pathological indices were observed in lung sections, which showed substantially reduced gene expression of inflammatory mediators in tissues upon Alg@AS CNG treatment. We further showed that the Alg@AS CNGs could inhibit H1N1 infection by binding to viral particles and lowering the oxidative stress in cells. © 2022, The Authors. All rights reserved.

关键词： Nanogels

来源：评论

学校读者我要写书评

暂无评论

Planet Masses, Radii, and Orbits from NASA’s K2 Mission

arXiv

引用

arXiv 2025年

作者： Howard, Andrew W. Sinukoff, Evan Blunt, Sarah Petigura, Erik A. Crossfield, Ian J.M. Isaacson, Howard Kosiarek, Molly Rubenzahl, Ryan A. Brewer, John M. Fulton, Benjamin J. Dressing, Courtney D. Hirsch, Lea A. Knutson, Heather Livingston, John H. Mills, Sean M. Roy, Arpita Weiss, Lauren M. Benneke, Bjorn Ciardi, David R. Christiansen, Jessie L. Cochran, William D. Crepp, Justin R. Gonzales, Erica Hansen, Brad M.S. Hardegree-Ullman, Kevin Howell, Steve B. Lépine, Sébastien Martinez, Arturo O. Rogers, Leslie A. Schlieder, Joshua E. Werner, Michael Polanski, Alex S. Angelo, Isabel Beard, Corey Behmard, Aida Bouma, Luke G. Brinkman, Casey L. Chontos, Ashley Dai, Fei Dalba, Paul A. Giacalone, Steven Grunblatt, Samuel K. Hill, Michelle L. Kane, Stephen R. Lubin, Jack Mayo, Andrew W. Mocnik, Teo Akana Murphy, Joseph M. Rice, Malena Rosenthal, Lee J. Tyler, Dakotah Van Zandt, Judah Yee, Samuel W. Department of Astronomy California Institute of Technology PasadenaCA United States Institute for Astronomy University of Hawaii 2680 Woodlawn Drive HonoluluHI United States Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States Department of Astronomy & Astrophysics University of California Santa CruzCA United States Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Department of Physics & Astronomy University of California Los Angeles Los AngelesCA United States Department of Physics and Astronomy University of Kansas LawrenceKS United States Astronomy Department University of California BerkeleyCA United States Department of Physics and Astronomy San Francisco State University 1600 Holloway Ave. San FranciscoCA94132 United States IPAC - NASA Exoplanet Science Institute California Institute of Technology 770 S. Wilson Ave PasadenaCA United States Department of Chemical & Physical Sciences University of Toronto Mississauga 3359 Mississauga Road MississaugaONL5L 1C6 Canada Geological and Planetary Sciences California Institute of Technology PasadenaCA 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 The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Astrophysics & Space Institute Schmidt Sciences New YorkNY10011 United States Department of Physics and Astronomy University of Notre Dame Notre DameIN46556 United States Institut de Recherche sur les Exoplanètes Université de Montréal MontréalQC Canada McDonald Observatory Center for Planetary Systems Habitability The University of Texas AustinTX United States Department of Physics and Astronomy University of Toledo ToledoOH4

We report the masses, sizes, and orbital properties of 86 planets orbiting 55 stars observed by NASA’s K2 Mission with follow-up Doppler measurements by the HIRES spectrometer at the W. M. Keck Observatory and the Automated Planet Finder at Lick Observatory. Eighty-one of the planets were discovered from their transits in the K2 photometry, while five were found based on subsequent Doppler measurements of transiting planet host stars. The sizes of the transiting planets range from Earth-size to larger than Jupiter (1–3 R is typical), while the orbital periods range from less than a day to a few months. For 32 of the planets, the Doppler signal was detected with significance greater than 5-σ (51 were detected with >3-σ significance). An important characteristic of this catalog is the use of uniform analysis procedures to determine stellar and planetary properties. This includes the transit search and fitting procedures applied to the K2 photometry, the Doppler fitting techniques applied to the radial velocities, and the spectral modeling to determine bulk stellar parameters. Such a uniform treatment will make the catalog useful for statistical studies of the masses, densities, and system architectures of exoplanetary systems. This work also serves as a data release for all previously unpublished RVs and associated stellar activity indicators obtained by our team for these systems, along with derived stellar and planet parameters. © 2025, CC BY.

关键词： NASA

来源：评论

学校读者我要写书评

暂无评论

Robot Hand Interaction Using Plastic Deformation Control with Inner Position Loop

Robot Hand Interaction Using Plastic Deformation Control wit...

引用

IEEE/ASME (AIM) International Conference on Advanced Intelligent Mechatronics

作者： Kenichi Murakami Koki Ishimoto Taku Senoo Masatoshi Ishikawa Data Science Research Division Information Technology Center The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo Japan Department of Information Physics and Computing The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo Japan Electrical Systems and Control Engineering Program Graduate School of Advanced Science and Engineering Hiroshima University 1-4-1 Kagamiyama Higashi-Hiroshima City Hiroshima Japan

ISBN: (数字)9781728167947

ISBN: (纸本)9781728167954

In this study, the inner position loop addition for plastic deformation control of the error robustness of the model and actual parameters is proposed. The inner position loop is a type of position feedback control based on the estimation of model parameters and dynamics of robots. This position control system with proportional and derivative gains modifies the trajectory of the end effector close to the desired trajectory. The robustness of the proposed control scheme is evaluated by comparing it with plastic deformation control without an inner position loop in both simulation and actual environments. Finally, the stable reaction with the proposed control is demonstrated for the case where a human pushes the robot finger.

关键词： Strain Plastics Force Deformable models Robots Friction Trajectory

来源：评论

学校读者我要写书评

暂无评论

Fe-vacancy ordered fe4se5—the insulating parent phase of fese superconductor

arXiv

引用

arXiv 2020年

作者： Yeh, Keng-Yu Chen, Yan-Rai Lo, Tung-Sheng Wu, Phillip M. Wang, Ming-Jye Chang-Liao, Kuei-Shu Wu, Maw-Kuen Institute of Physics Academia Sinica Taipei115 Taiwan Taiwan International Graduate Student Program Academia Sinica Taipei115 Taiwan Institute of Astronomy and Astrophysics Academia Sinica Taipei115 Taiwan Department of Engineering and System Science National Tsing Hua University Hsinchu300 Taiwan BitSmart LLC San MateoCA94403 United States

We have carried out a detailed study to investigate the existence of an insulating parent phase for FeSe superconductor. The insulating Fe4Se5 with √5 × √5 Fe-vacancy order shows a 3D-Mott variable range hopping behavior with a Verwey-like electronic correlation at around 45 K. The application of the RTA process at 450 °C results in the destruction of Fe-vacancy order and induces more electron carriers by increasing the Fe3+ valence state. Superconductivity emerges with Tc ~ 8K without changing the chemical stoichiometry of the sample after the RTA process by resulting in the addition of extra carriers in favor of superconductivity. © 2020, CC-BY-NC-SA.

关键词： Insulation

来源：评论

学校读者我要写书评

暂无评论

Direct observational evidence of multi-epoch massive star formation in G24.47+0.49

arXiv

引用

arXiv 2024年

作者： Saha, Anindya Tej, Anandmayee Liu, Hong-Li Liu, Tie Garay, Guido Goldsmith, Paul F. Lee, Chang Won He, Jinhua Juvela, Mika Bronfman, Leonardo Baug, Tapas Vázquez-Semadeni, Enrique Sanhueza, Patricio Li, Shanghuo Chibueze, James O. Bhadari, N.K. Dewangan, Lokesh K. Das, Swagat Ranjan Xu, Feng-Wei Issac, Namitha Hwang, Jihye Tóth, L. Viktor Indian Institute of Space Science and Technology Kerala Thiruvananthapuram695 547 India Department of Astronomy Yunnan University Kunming650091 China Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China Departamento de Astronomía Universidad de Chile Las Condes Santiago7550000 Chile Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive PasadenaCA91109 United States 217 Gajeong-ro Yuseong-gu Daejeon34113 Korea Republic of Korea Astronomy and Space Science Institute 776 Daedeokdae-ro Yuseong-gu Daejeon34055 Korea Republic of Yunnan Observatories Chinese Academy of Sciences Phoenix Mountain East Suburb of Kunming Yunnan650216 China at Cerro Calán Camino El Observatorio #1515 Las Condes Santiago Chile Department of Physics University of Helsinki P.O. box 64 FI- 00014 Finland Satyendra Nath Bose National Centre for Basic Sciences Block-JD Sector-III Kolkata Salt Lake700 106 India 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 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 Department of Mathematical Sciences University of South Africa Cnr Christian de Wet Rd and Pioneer Avenue Florida Park Roodepoort1709 South Africa Department of Physics and Astronomy Faculty of Physical Sciences University of Nigeria Carver Building 1 University Road Nsukka410001 Nigeria Physical Research Laboratory Navrangpura Ahm

Using new continuum and molecular line data from the ALMA Three-millimeter Observations of Massive Star-forming Regions (ATOMS) survey and archival VLA, 4.86 GHz data, we present direct observational evidence of hierarchical triggering relating three epochs of massive star formation in a ring-like H II region, G24.47+0.49. We find from radio flux analysis that it is excited by a massive star(s) of spectral type O8.5V–O8V from the first epoch of star formation. The swept-up ionized ring structure shows evidence of secondary collapse, and within this ring a burst of massive star formation is observed in different evolutionary phases, which constitutes the second epoch. ATOMS spectral line (e.g., HCO+(1–0)) observations reveal an outer concentric molecular gas ring expanding at a velocity of ~ 9 km s−1, constituting the direct and unambiguous detection of an expanding molecular ring. It harbors twelve dense molecular cores with surface mass density greater than 0.05 g cm−2, a threshold typical of massive star formation. Half of them are found to be subvirial, and thus in gravitational collapse, making them third epoch of potential massive star-forming sites. Copyright © 2024, The Authors. All rights reserved.

关键词： Stars

来源：评论

学校读者我要写书评

暂无评论

Constraints on VHE gamma-ray emission of Flat Spectrum Radio Quasars with the MAGIC telescopes

arXiv

引用

arXiv 2024年

作者： Abe, S. Abhir, J. Abhishek, A. Acciari, V.A. Aguasca-Cabot, A. Agudo, I. Aniello, T. Ansoldi, S. Antonelli, L.A. Engels, A. Arbet Arcaro, C. Artero, M. Asano, K. Babić, A. Baquero, A. de Almeida, U. Barres Barrio, J.A. Batković, I. Bautista, A. Baxter, J. González, J. Becerra Bednarek, W. Bernardini, E. Bernete, J. Berti, A. Bigongiari, C. Biland, A. Blanch, O. Bonnoli, G. Bošnjak, Ž. Bronzini, E. Burelli, I. Busetto, G. Buson, S. Campoy-Ordaz, A. Carosi, A. Carosi, R. Carretero-Castrillo, M. Castro-Tirado, A.J. Cerasole, D. Ceribella, G. Chai, Y. Cifuentes, A. Ciprini, S. Colombo, E. Contreras, J.L. Cortina, J. Covino, S. D’Amico, G. D’Ammando, F. D’Elia, V. Da Vela, P. Dazzi, F. De Angelis, A. De Lotto, B. de Menezes, R. Del Popolo, A. Delfino, M. Delgado, J. Mendez, C. Delgado Di Pierro, F. Di Tria, R. Di Venere, L. Donini, A. Dorner, D. Doro, M. Elsaesser, D. Escudero, J. Fariña, L. Fattorini, A. Foffano, L. Font, L. Fröse, S. Fukami, S. Fukazawa, Y. López, R.J. García Garczarczyk, M. Gasparyan, S. Gaug, M. Paiva, J.G. Giesbrecht Giglietto, N. Giordano, F. Gliwny, P. Gradetzke, T. Grau, R. Green, D. Green, J.G. Günther, P. Hadasch, D. Hahn, A. Hassan, T. Heckmann, L. Herrera, J. Hrupec, D. Hütten, M. Imazawa, R. Ishio, K. Martínez, I. Jiménez Jormanainen, J. Kayanoki, T. Kerszberg, D. Kobayashi, Y. Kouch, P.M. Kubo, H. Kushida, J. Láinez, M. Lamastra, A. 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. Martínez-Chicharro, M. Mas-Aguilar, A. Mazin, D. Menchiari, S. Mender, S. Miceli, D. Miener, T. Miranda, J.M. Mirzoyan, R. González, M. Molero Molina, E. Mondal, H.A. Moralejo, A. Morcuende, D. Nakamori, T. Nanci, C. Neustroev, V. Nickel, L. Rosillo, M. Nievas Nigro, C. Nikolić, L. Nilsson, K. Nishijima, K. The University of Tokyo Chiba Kashiwa277-8582 Japan ETH Zürich ZürichCH-8093 Switzerland Università di Siena INFN Pisa SienaI-53100 Italy Bellaterra BarcelonaE-08193 Spain Universitat de Barcelona ICCUB IEEC-UB BarcelonaE-08028 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 GarchingD-85748 Germany Università di Padova INFN PadovaI-35131 Italy Zagreb10000 Croatia IPARCOS Institute EMFTEL Department Universidad Complutense de Madrid MadridE-28040 Spain URCA RJ Rio de Janeiro22290-180 Brazil Instituto de Astrofísica de Canarias Dpto. de Astrofísica Universidad de La Laguna Tenerife La LagunaE-38200 Spain University of Lodz Faculty of Physics and Applied Informatics Department of Astrophysics Lodz90-236 Poland Centro de Investigaciones Energéticas Medioambientales y Tecnológicas MadridE-28040 Spain Departament de Física CERES-IEEC Universitat Autònoma de Barcelona BellaterraE-08193 Spain Università di Pisa INFN Pisa PisaI-56126 Italy INFN MAGIC Group INFN Sezione di Bari Dipartimento Interateneo di Fisica dell’Università e del Politecnico di Bari BariI-70125 Italy Department for Physics and Technology University of Bergen Norway INFN MAGIC Group INFN Sezione di Torino Università degli Studi di Torino TorinoI-10125 Italy Universität Würzburg WürzburgD-97074 Germany Technische Universität Dortmund DortmundD-44221 Germany Japanese MAGIC Group: Physics Program Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima739-8526 Japan ZeuthenD-15738 Germany Armenian MAGIC Group: ICRANet-Armenia Yerevan0019 Armenia Croatian MAGIC Group Josip Juraj Strossmayer University of Osijek Department of Physics Osijek31000 Croatia Finnish MAGIC Group Finnish Centre for Astronomy with ESO Department of Physics and Astronomy University of Turku T

Flat spectrum radio quasars (FSRQs) constitute a class of jetted active galaxies characterized by a very luminous accretion disk, prominent and rapidly moving line-emitting cloud structures (Broad Line Region, BLR), and a surrounding dense dust structure known as dusty torus. The intense radiation field of the accretion disk strongly determines the observational properties of FSRQs. While hundreds of such sources have been detected at GeV energies, only a handful of them exhibit emission in the very-high-energy (VHE, E 100 GeV) range. This study presents the results and interpretation derived from a cumulative observation period of 174 hours dedicated to nine FSRQs conducted with the MAGIC telescopes from 2008 to 2020. Our findings indicate no statistically significant (≥ 5 σ) signal for any of the studied sources, resulting in upper limits on the emission within the VHE energy range. In two of the sources, we derived quite stringent constraints on the γ-ray emission in the form of upper limits. Our analysis focuses on modeling the VHE emission of these two sources in search for hints of absorption signatures within the broad line region (BLR) radiation field. For these particular sources, constraints on the distance between the emission region and the central black hole are derived using a phenomenological model. Subsequently, these constraints are tested using a framework based on a leptonic model. Copyright © 2024, The Authors. All rights reserved.

关键词： Germanium alloys

来源：评论

学校读者我要写书评

暂无评论

The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). IX. Physical Properties and Spatial Distribution of Cores in IRDCs

引用

Astrophysical Journal 2023年第2期950卷 148-148页

作者： Morii, Kaho Sanhueza, Patricio Nakamura, Fumitaka Zhang, Qizhou Sabatini, Giovanni Beuther, Henrik Lu, Xing Li, Shanghuo Garay, Guido Jackson, James M. Olguin, Fernando A. Tafoya, Daniel Tatematsu, Ken’ichi Izumi, Natsuko Sakai, Takeshi Silva, Andrea Department of Astronomy Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Astronomical Science Program The Graduate University for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo 181-8588 Japan Center for Astrophysics Harvard & Smithsonian 60 Garden Street Cambridge 02138 MA United States INAF—Istituto di Radioastronomia—Italian node of the ALMA Regional Centre (It-ARC) Via Gobetti 101 Bologna I-40129 Italy INAF Osservatorio Astrofisico di Arcetri Largo E. Fermi 5 Firenze I-50125 Italy Max Planck Institute for Astronomy Konigstuhl 17 Heidelberg D-69117 Germany Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai 200030 China Departamento de Astronomía Universidad de Chile Las Condes Santiago 7550000 Chile Green Bank Observatory 155 Observatory Rd Green Bank 24944 WV United States Institute of Astronomy Department of physics National Tsing Hua University Hsinchu 30013 Taiwan Department of Space Earth and Environment Chalmers University of Technology Onsala Space Observatory Onsala SE-439 92 Sweden Academia Sinica Institute of Astronomy and Astrophysics 11F of AS/NTU Astronomy-Mathematics Building No.1 Section 4 Roosevelt Road Taipei 10617 Taiwan Graduate School of Informatics and Engineering The University of Electro-Communications Chofu Tokyo 182-8585 Japan

The initial conditions found in infrared dark clouds (IRDCs) provide insights on how high-mass stars and stellar clusters form. We have conducted high-angular resolution and high-sensitivity observations toward thirty-nine massive IRDC clumps, which have been mosaicked using the 12 and 7 m arrays from the Atacama Large Millimeter/submillimeter Array. The targets are 70 μm dark massive (220-4900 M _⊙), dense (>10⁴ cm⁻³), and cold (∼10-20 K) clumps located at distances between 2 and 6 kpc. We identify an unprecedented number of 839 cores, with masses between 0.05 and 81 M _⊙ using 1.3 mm dust continuum emission. About 55% of the cores are low-mass (<1 M _⊙), whereas ≲1% (7/839) are high-mass (≳27 M _⊙). We detect no high-mass prestellar cores. The most massive cores (MMC) identified within individual clumps lack sufficient mass to form high-mass stars without additional mass feeding. We find that the mass of the MMCs is correlated with the clump surface density, implying denser clumps produce more massive cores. There is no significant mass segregation except for a few tentative detections. In contrast, most clumps show segregation once the clump density is considered instead of mass. Although the dust continuum emission resolves clumps in a network of filaments, some of which consist of hub-filament systems, the majority of the MMCs are not found in the hubs. Our analysis shows that high-mass cores and MMCs have no preferred location with respect to low-mass cores at the earliest stages of high-mass star formation. © 2023. The Author(s). Published by the American Astronomical Society.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：