检索结果-内蒙古大学图书馆

arXiv 2024年

作者： Liu, Mingjun Zhang, Yijia Wang, Yun Xue, Rui Buckley, David Howell, D. Andrew Jin, Chichuan Li, Wenxiong Monageng, Itumeleng Pan, Haiwu Sun, Ning-Chen Tinyanont, Samaporn Wang, Lingzhi Yuan, Weimin An, Jie Andrews, Moira Anutarawiramkul, Rungrit Butpan, Pathompong Cheng, Huaqing Dai, Cui-Yuan Dai, Lixin Farah, Joseph Feng, Hua Fu, Shaoyu Guo, Zhen Jiang, Shuaiqing Li, An Li, Dongyue Liang, Yifang Liu, Heyang Liu, Xing Liu, Yuan Mao, Jirong McCully, Curtis Newsome, Megan Gonzalez, Estefania Padilla Pan, Xin Sun, Xinxiang Terreran, Giacomo Wang, Ze-Rui Wu, Qinyu Xiao, Hubing Xiong, Dingrong Xu, Dong Xu, Xinpeng Xue, Suijian Yang, Haonan Yang, Jun Zhang, Jin Zhang, Wenda Zhang, Wenjie Zou, Hu National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Beijing100101 China School of Astronomy and Space Science University of Chinese Academy of Sciences 19A Yuquan Road Beijing100049 China Department of Astronomy Tsinghua University Beijing100084 China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing210034 China Department of Physics Zhejiang Normal University Jinhua321004 China South African Astronomical Observatory Cape Town7935 South Africa Department of Astronomy University of Cape Town Rondebosch7701 South Africa Department of Physics University of the Free State Bloemfontein9300 South Africa Las Cumbres Observatory 6740 Cortona Drive Suite 102 GoletaCA93117-5575 United States Department of Physics University of California Santa BarbaraCA93106-9530 United States Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Beijing102206 China National Astronomical Research Institute of Thailand 260 Moo 4 Donkaew Maerim Chiang Mai50180 Thailand National Astronomical Observatories Chinese Academy of Sciences Beijing China CAS Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing China School of Astronomy and Space Science Nanjing University Nanjing210023 China Key Laboratory of Modern Astronomy and Astrophysics Nanjing University Ministry of Education Nanjing210023 China Department of Physics University of Hong Kong Pokfulam Road Hong Kong Las Cumbres Observatory 6740 Cortona Drive Suite 102 GoletaCA93117-557 United States Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Instituto de Física y Astronomía Universidad de Valparaíso ave. Gran Bretaña 1111 Casilla 5030 Valparaíso Chile Millennium Institute of Astrophysics Nuncio Monseñor Sotero Sanz 100 Of. 104 Providencia Santiago Chile

Blazars are often observed to flare across multiple wavelengths. Orphan flares from blazars have been only detected a few times, providing an opportunity to understand the structure of the jet in the accreting system. We report a remarkable orphan X-ray flare from a blazar candidate EP240709a, detected by Einstein Probe (EP) in July 2024. The multi-band spectral properties and variability support EP240709a as a high-energy peaked BL Lacertae-type object. The flux in 0.5-10 keV increases by at least 28 times to the value of low state in 2020, with non-detection of remarkable flaring in other bands during the same period. EP240709a exhibits the harder-when-brighter tendency in the X-ray band during the orphan flare, while its infrared-optical spectra are featureless. We employ one-zone and two-zone leptonic synchrotron self-Compton models to perform the spectral energy distribution fitting. Detecting this rare orphan flare shows the potential of EP in discovering peculiar activities from AGN in high-cadence X-ray sky surveys. © 2024, CC BY.

关键词： Probes

来源：评论

学校读者我要写书评

暂无评论

Optical and ultraviolet monitoring of the black hole X-ray binary MAXI J1820+070/ASASSN-18ey for 18 months

arXiv

引用

arXiv 2021年

作者： Sai, Hanna Wang, Xiaofeng Wu, Jianfeng Lin, Jie Feng, Hua Zhang, Tianmeng Li, Wenxiong Zhang, Jujia Mo, Jun Sun, Tianrui Ehgamberdiev, Shuhrat A. Mirzaqulov, Davron Rui, Liming Lin, Weili Zhao, Xulin Lin, Han Zhang, Jicheng Zhang, Xinghan Zhao, Yong Li, Xue Xiang, Danfeng Wang, Lingzhi Wu, Chengyuan Tsinghua University Beijing100084 China Beijing Planetarium Beijing Academy of Science and Technology Beijing100044 China Siming District Xiamen Fujian361005 China Department of Astronomy Tsinghua University Beijing100084 China Department of Engineering Physics Tsinghua University Beijing100084 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing101408 China Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing210008 China Chinese Center for Antarctic Astronomy Nanjing210008 China School of Astronomy and Space Science University of Science and Technology of China Hefei230026 China Ulugh Beg Astronomical Institute Uzbekistan Academy of Sciences Uzbekistan Tashkent100052 Uzbekistan School of Science Tianjin University of Technology Tianjin300384 China University of Chinese Academy of Sciences Beijing100049 China National Astronomical Observatory of China Chinese Academy of Sciences Beijing100012 China Chinese Academy of Sciences South America Center for Astronomy National Astronomical Observatories CAS Beijing100101 China

MAXI J1820+070 is a low-mass black hole X-ray binary system with high luminosity in both optical and X-ray bands during the outburst periods. We present extensive photometry in X-ray, ultraviolet, and optical bands, as well as densely-cadenced optical spectra, covering the phase from the beginning of optical outburst to ∼550 days. During the rebrightening process, the optical emission preceded the X-ray by 20.80 ± 2.85 days. The spectra are characterized by blue continua and emission features of Balmer series, He i, He ii lines and broad Bowen blend. The pseudo equivalent width (pEW) of emission lines are found to show anticorrelations with the X-ray flux measured at comparable phases, which is due to the increased suppression by the optical continuum. At around the X-ray peak, the full width at half maximums (FWHMs) of Hβ and He ii λ4686 tend to stabilize at 19.4 Angstrom and 21.8 Angstrom, which corresponds to the line forming region at a radius of 1.7 and 1.3 Ro within the disk. We further analyzed the absolute fluxes of the lines and found that the fluxes of Hβ and He ii λ4686 show positive correlations with the X-ray flux, favoring that the irradiation model is responsible for the optical emission. However, the fact that X-ray emission experiences a dramatic flux drop at t∼200 days after the outburst, while the optical flux only shows little variations suggests that additional energy such as viscous energy may contribute to the optical radiation in addition to the X-ray irradiation. © 2021, CC BY.

关键词： Stars

来源：评论

学校读者我要写书评

暂无评论

Detailed spectrophotometric analysis of the superluminous and fast evolving SN 2019neq

arXiv

引用

arXiv 2023年

作者： Fiore, Achille Benetti, Stefano Tartaglia, Leonardo Jerkstrand, Anders Salmaso, Irene Tomasella, Lina Morales-Garoffolo, Antonia Geier, Stefan Elias-Rosa, Nancy Cappellaro, Enrico Wang, Xiaofeng Mo, Jun Chen, Zhihao Yan, Shengyu Pastorello, Andrea Mazzali, Paolo A. Ciolfi, Riccardo Cai, Yongzhi Fraser, Morgan Gutiérrez, Claudia P. Karamehmetoglu, Emir Kuncarayakti, Hanindyo Moran, Shane Ochner, Paolo Reguitti, Andrea Reynolds, Thomas M. Valerin, Giorgio Institut für Theoretische Physik Goethe Universität Max-von-Laue-Str. 1 Frankfurt am Main60438 Germany INFN-TIFPA Trento Institute for Fundamental Physics and Applications Via Sommarive 14 TrentoI-38123 Italy INAF - Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 PadovaI-35122 Italy INAF - Osservatorio Astronomico d’Abruzzo via M. Maggini snc TeramoI-64100 Italy The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-10691 Sweden Dipartimento di Fisica e Astronomia ‘G. Galilei’ Università di Padova Vicolo dell’Osservatorio 3 PadovaI-35122 Italy Department of Applied Physics School of Engineering University of Cádiz Campus of Puerto Real CádizE-11519 Spain Instituto de Astrofisíca de Canarias Tenerife Canary Islands La Laguna38200 Spain GRANTECAN Cuesta de San José s/n La Palma Breña Baja38712 Spain Campus UAB Carrer de Can Magrans s/n Barcelona08193 Spain Tsinghua University Beijing100084 China Beijing Planetarium Beijing Academy of Science and Technology Beijing100044 China Astrophysics Research Institute Liverpool John Moores University LiverpoolL3 5RF United Kingdom Max-Planck Institute for Astrophysics Garching Germany INFN – Sezione di Padova Via Francesco Marzolo 8 PadovaI-35131 Italy Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China School of Physics O’Brien Centre for Science North University College Dublin Belfield Dublin 4 Ireland Gran Capità 2-4 Edifici Nexus Desp. 201 BarcelonaE-08034 Spain Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain Department of Physics and Astronomy Aarhus University Ny Munkegade 120 Aarhus CDK-8000 Denmark Department of Physics and Astronomy University of Turku Vesilinnantie 5 20500 Finland INAF - Osse

SN 2019neq was a very fast evolving superluminous supernova. At a redshift Z = 0.1059, its peak absolute magnitude was -21.5 ± 0.2 mag in g band. In this work, we present data and analysis from an extensive spectrophotometric follow-up campaign using multiple observational facilities. Thanks to a nebular spectrum of SN 2019neq, we investigated some of the properties of the host galaxy at the location of SN 2019neq and found that its metallicity and specific star formation rate are in a good agreement with those usually measured for SLSNe-I hosts. We then discuss the plausibility of the magnetar and the circumstellar interaction scenarios to explain the observed light curves, and interpret a nebular spectrum of SN 2019neq using published sumo radiative-transfer models. The results of our analysis suggest that the spindown radiation of a millisecond magnetar with a magnetic field B 6 × 1014 G could boost the luminosity of SN 2019neq. Copyright © 2023, The Authors. All rights reserved.

关键词： Supernovae

来源：评论

学校读者我要写书评

暂无评论

On the diversity of strongly-interacting Type IIn supernovae

arXiv

引用

arXiv 2024年

作者： Salmaso, I. Cappellaro, E. Tartaglia, L. Anderson, J.P. Benetti, S. Bronikowski, M. Cai, Y.-Z. Charalampopoulos, P. Chen, T.-W. Concepcion, E. Elias-Rosa, N. Galbany, L. Gromadzki, M. Gutiérrez, C.P. Kankare, E. Lundqvist, P. Matilainen, K. Mazzali, P.A. Moran, S. Müller-Bravo, T.E. Nicholl, M. Pastorello, A. Pessi, P.J. Pessi, T. Petrushevska, T. Pignata, G. Reguitti, A. Sollerman, J. Srivastav, S. Stritzinger, M. Tomasella, L. Valerin, G. INAF-Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 Padova35122 Italy INAF-Osservatorio Astronomico d’Abruzzo Via M. Maggini snc Teramo64100 Italy European Southern Observatory Alonso de Córdova 3107 Casilla 19 Santiago Chile Millennium Institute of Astrophysics MAS Nuncio Monsenor Sotero Sanz 100 Off. 104 Providencia Santiago Chile Center for Astrophysics and Cosmology University of Nova Gorica Vipavska 11c Ajdovščina5270 Slovenia Yunnan Observatories Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China Department of Physics and Astronomy University of Turku Vesilinnantie 5 20500 Finland Graduate Institute of Astronomy National Central University 300 Jhongda Road Jhongli32001 Taiwan Campus UAB Carrer de Can Magrans s/n Barcelona08193 Spain Castelldefels Barcelona08860 Spain Astronomical Observatory University of Warsaw Al. Ujazdowskie 4 Warszawa00-478 Poland The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova Stockholm106 91 Sweden Nordic Optical Telescope Aarhus Universitet Rambla José Ana Fernández Pérez 7 local 5 San Antonio Breña Baja Santa Cruz TenerifeE-38711 Spain Tuorla Observatory Department of Physics and Astronomy University of Turku Vesilinnantie 5 Turku20014 Finland Astrophysics Research Institute Liverpool John Moores University ic2 146 Brownlow Hill LiverpoolL3 5RF United Kingdom Max-Planck Institut für Astrophysik Karl-Schwarzschild-Str. 1 Garching bei München85741 Germany Astrophysics Research Centre School of Mathematics and Physics Queens University Belfast BelfastBT7 1NN United Kingdom Instituto de Estudios Astrofísicos Facultad de Ingeniería y Ciencias Universidad Diego Portales Av. Ejército Libertador 441 Santiago Chile Instituto de Alta Investigación Universidad de Ta

Context. Massive stars experience strong mass-loss rates, producing a dense, H-rich circumstellar medium (CSM). After the explosion, the collision and continued interaction of the supernova (SN) ejecta with the CSM power the light curve through the conversion of kinetic energy into radiation. When the interaction is strong, the light curve shows a broad peak and high luminosity lasting for several months. Also the spectral evolution is slower, compared to non-interacting SNe. Energetic shocks between the ejecta and the CSM create the ideal conditions for particle acceleration and production of high-energy (HE) neutrinos above 1 TeV. Aims. We study four strongly-interacting Type IIn SNe: 2021acya, 2021adxl, 2022qml, and 2022wed to highlight their peculiar characteristics, derive the kinetic energy of the explosion and the characteristics of the CSM, infer clues on the possible progenitors and their environment and relate them to the production of HE neutrinos. Methods. We analysed spectro-photometric data of a sample of interacting SNe to determine their common characteristics and derive physical properties (radii and masses) of the CSM and ejecta kinetic energies to compare them to HE neutrino production models. Results. The SNe analysed in this sample exploded in dwarf, star-forming galaxies and they are consistent with energetic explosions and strong interaction with the surrounding CSM. For SNe 2021acya and 2022wed, we find high CSM masses and mass-loss rates, linking them to very massive progenitors. For SN 2021adxl, the spectral analysis and less extreme CSM mass suggest a stripped-envelope massive star as possible progenitor. SN 2022qml is marginally consistent with being a Type Ia thermonuclear explosion embedded in a dense CSM. The mass-loss rates for all SNe are consistent with the expulsion of several solar masses of material during eruptive episodes in the last few decades before the explosion. Finally, we find that the SNe in our sample are marginally co

关键词： Kinetic energy

来源：评论

学校读者我要写书评

暂无评论

Matter ejections behind the highs and lows of the transitional millisecond pulsar PSR J1023+0038

arXiv

引用

arXiv 2023年

作者： Baglio, M.C. Zelati, F. Coti Campana, S. Busquet, G. D’Avanzo, P. Giarratana, S. Giroletti, M. Ambrosino, F. Crespi, S. Zanon, A. Miraval Hou, X. Li, D. Li, J. Wang, P. Russell, D.M. Torres, D.F. Alabarta, K. Casella, P. Covino, S. Bramich, D.M. de Martino, D. Méndez, M. Motta, S.E. Papitto, A. Saikia, P. Vincentelli, F. Center for Astro Particle and Planetary Physics New York University Abu Dhabi P.O. Box 129188 Abu Dhabi United Arab Emirates INAF Osservatorio Astronomico di Brera Via Bianchi 46 LC MerateI-23807 Italy Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain Carrer Gran Capità 2–4 BarcelonaE-08034 Spain c/ Martí Franquès 1 BarcelonaE-08028 Spain c/ Martí Franquès 1 BarcelonaE-08028 Spain INAF Istituto di Radioastronomia via Gobetti 101 BolognaI-40129 Italy Department of Physics and Astronomy University of Bologna via Gobetti 93/2 BolognaI-40129 Italy INAF Osservatorio Astronomico di Roma Via Frascati 33 RM Monteporzio CatoneI-00078 Italy INAF–Istituto di Astrofisica e Planetologia Spaziali Via Fosso del Cavaliere 100 RomeI-00133 Italy Sapienza Università di Roma Piazzale Aldo Moro 5 RomeI-00185 Italy ASI - Agenzia Spaziale Italiana Via del Politecnico snc RomeI-00133 Italy Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China Research Center for Intelligent Computing Platforms Zhejiang Laboratory Hangzhou311100 China CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Hefei China School of Astronomy and Space Science University of Science and Technology of China Hefei China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Beijing102206 China Passeig Lluís Companys 23 BarcelonaE-08010 Spain Division of Engineering New York University Abu Dhabi P.O. Box 129188 Saadiyat Island Abu Dhabi United Arab Emirates INAF−-Osservatorio Astronomico di Capodimonte Salita Moiariello 16 NapoliI-80131 Italy Kaptey

Transitional millisecond pulsars are an emerging class of sources that link low-mass X-ray binaries to millisecond radio pulsars in binary systems. These pulsars alternate between a radio pulsar state and an active low-luminosity X-ray disc state. During the active state, these sources exhibit two distinct emission modes (high and low) that alternate unpredictably, abruptly, and incessantly. X-ray to optical pulsations are observed only during the high mode. The root cause of this puzzling behaviour remains elusive. This paper presents the results of the most extensive multi-wavelength campaign ever conducted on the transitional pulsar prototype, PSR J1023+0038, covering from the radio to X-rays. The campaign was carried out over two nights in June 2021 and involved 12 different telescopes and instruments, including XMM-Newton, HST, VLT/FORS2 (in polarimetric mode), ALMA, VLA, and FAST. By modelling the broadband spectral energy distributions in both emission modes, we show that the mode switches are caused by changes in the innermost region of the accretion disc. These changes trigger the emission of discrete mass ejections, which occur on top of a compact jet, as testified by the detection of at least one short-duration millimetre flare with ALMA at the high-to-low mode switch. The pulsar is subsequently re-enshrouded, completing our picture of the mode switches. © 2023, CC BY.

关键词： Pulsars

来源：评论

学校读者我要写书评

暂无评论

The fast rise of the unusual Type IIL/IIb SN 2018ivc

arXiv

引用

arXiv 2024年

作者： Reguitti, Andrea Dastidar, R. Pignata, G. Maeda, K. Moriya, T.J. Kuncarayakti, H. Rodríguez, Ó. Bersten, M. Anderson, J.P. Charalampopoulos, P. Fraser, M. Gromadzki, M. Young, D.R. Benetti, S. Cai, Y.-Z. Elias-Rosa, N. Lundqvist, P. Carini, R. Cosentino, S.P. Galbany, L. Gonzalez-Bañuelos, M. Gutiérrez, C.P. Kopsacheili, M. Pineda, J.A.G. Ramirez, M. MerateI-23807 Italy INAF – Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 PadovaI-35122 Italy Instituto de Astrofìsica Universidad Andres Bello Fernandez Concha 700 Las Condes RM Santiago8320000 Chile Nuncio Monseñor Sótero Sanz 100 Providencia RM Santiago8320000 Chile Instituto de Alta Investigación Universidad de Tarapacá Casilla 7D Arica Chile Department of Astronomy Kyoto University Kitashirakawa-Oiwake-cho Sakyo-ku Kyoto606-8502 Japan National Astronomical Observatory of Japan National Institutes of Natural Sciences Graduate Institute for Advanced Studies SOKENDAI 2-21-1 Osawa Mitaka Tokyo181-8588 Japan School of Physics and Astronomy Monash University ClaytonVIC3800 Australia Department of Physics and Astronomy University of Turku TurkuFI-20014 Finland University of Turku FI-20014 Finland CCT-CONICET-UNLP. Paseo del Bosque S/N La PlataB1900FWA Argentina Facultad de Ciencias Astronómicas y Geofísicas Universidad Nacional de La Plata Paseo del Bosque S/N La PlataB1900FWA Argentina The University of Tokyo 5-1-5 Kashiwanoha Kashiwa Chiba277-8583 Japan European Southern Observatory Alonso de Córdova 3107 Casilla 19 Santiago8320000 Chile School of Physics O’Brien Centre for Science North University College Dublin Belfield Dublin 4 Ireland Astronomical Observatory University of Warsaw Al. Ujazdowskie 4 Warszawa00-478 Poland Astrophysics Research Centre School of Mathematics and Physics Queen’s University Belfast BelfastBT7 1NN United Kingdom Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China Campus UAB Carrer de Can Magrans s/n BarcelonaE-08193 Spain The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova StockholmSE-10691 Sweden I-00078 Italy Università d

We present an analysis of the photometric and spectroscopic dataset of the Type II supernova (SN) 2018ivc in the nearby (10 Mpc) galaxy Messier 77. Thanks to the high cadence of the CHASE survey, we observed the SN rising very rapidly by nearly three magnitudes in five hours (or 18 mag d−1). The r-band light curve presents four distinct phases: the maximum light is reached in just one day, then a first, rapid linear decline precedes a short-duration plateau. Finally, a long, slower linear decline lasted for one year. Following a radio rebrightening, we detected SN 2018ivc four years after the explosion. The early spectra show a blue, nearly featureless continuum, but the spectra evolve rapidly: after about 10 days a prominent Hα line starts to emerge, with a peculiar profile, but the spectra are heavily contaminated by emission lines from the host galaxy. He I lines, namely λλ5876,7065, are also strong. On top of the former, a strong absorption from the Na i doublet is visible, indicative of a non-negligible internal reddening. From its equivalent width, we derive a lower limit on the host reddening of AV 1.5 mag, while from the Balmer decrement and a match of the B − V colour curve of SN 2018ivc to that of the comparison objects, a host reddening of AV 3.0 mag is obtained. The spectra are similar to those of SNe II, but with strong He lines. Given the peculiar light curve and spectral features, we suggest SN 2018ivc could be a transitional object between the Type IIL and Type IIb SNe classes. In addition, we found signs of interaction with circumstellar medium in the light curve, making SN 2018ivc also an interacting event. Finally, we modelled the early multi-band light curves and photospheric velocity of SN 2018ivc to estimate the explosion and CSM physical parameters. Copyright © 2024, The Authors. All rights reserved.

关键词： Supernovae

来源：评论

学校读者我要写书评

暂无评论

Erratum: Formation of millisecond pulsars with helium white dwarfs, ultra-compact X-ray binaries, and gravitational wave sources

引用

Monthly Notices of the Royal Astronomical Society 2021年第3期506卷 4446-4446页

作者： Chen, Hai-Liang Tauris, Thomas M Han, Zhanwen Chen, Xuefei Yunnan Observatories Chinese Academy of Sciences (CAS) Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China Department of Physics and Astronomy Aarhus University Ny Munkegade 120 DK-8000 Aarhus C Denmark Aarhus Institute of Advanced Studies (AIAS) Aarhus University Høegh-Guldbergs Gade 6B DK-8000 Aarhus C Denmark University of the Chinese Academy of Sciences Yuquan Road 19 Shijingshan Block Beijing 100049 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing 100012 China

来源：评论

学校读者我要写书评

暂无评论

Constraining the Rastall parameters in static spacetimes with galaxy-scale strong gravitational lensing

arXiv

引用

arXiv 2019年

作者： Li, Rui Wang, Jiancheng Xu, Zhaoyi Guo, Xiaotong Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China University of Chinese Academy of Sciences Beijing100049 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China School of Astronomy and Space Science Nanjing University Nanjing Jiangsu210093 China

Recently, Rastall gravity is undergoing a significant surge in popularity. We obtain a power-law total mass-density profile for the inner region (within several effective radius) of early-type galaxies (ETGs) from the space-time structures which are described by the static spherically-symmetric solutions of Rastall gravity under the assumption of perfect fluid matter. We find that in the inner region of ETGs, the Rastall dimensionless parameter β = κλ determines the mass distribution. We then use 118 galaxy-galaxy strong gravitational lensing systems to constrain the Rastall dimensionless parameter β. We find that the mean value of β for total 118 ETGs is β = 0.163 ± 0.001(68% CL) with a minor intrinsic scatter of δ = 0.020 ± 0.001. Our work observationally illustrates the physical meaning of the Rastall dimensionless parameter in galaxy scale. From the Newtonian approximation of Rastall gravity, we also find that an absolute isothermal mass distribution for ETGs is not allowed in the framework of Rastall gravity. Copyright © 2019, The Authors. All rights reserved.

关键词： Galaxies

来源：评论

学校读者我要写书评

暂无评论

Convective overshooting in sdB stars using the k-ω model

arXiv

引用

arXiv 2018年

作者： Li, Yan Chen, Xing-hao Xiong, He-ran Guo, Jun-jun Chen, Xue-fei Han, Zhan-wen Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing100012 China University of Chinese Academy of Sciences Beijing100049 China

Mixing in the convective core is quite uncertain in core helium burning stars. In order to explore the overshooting mixing beyond the convective core, we incorporated the k-ω proposed by Li (2012, 2017) into MESA, and investigated the overshooting mixing in evolution of sdB models. We found that the development of the convective core can be divided into three stages. When the radiative temperature gradient ∇rad monotonically decreases from the stellar center, the overshooting mixing presents a behaviour of exponential decay similar with Herwig (2000), and the overshooting distance is to make ∇rad ∇ad at the boundary of the convective core, in agreement with the prediction of the self-driving mechanism Castellani, Giannone & Renzini (1971a). When the radiative temperature gradient ∇rad shows a minimum value in the convective core, the convective core may be divided into two convection zones if the minimum value of ∇rad is smaller than the adiabatic temperature gradient ∇ad. For the single-zone case, the overshooting mixing still shows an exponential decay behaviour, but the overshooting distance is much smaller than in the initial stage. For the double-zone case, the overshooting mixing is similar to that of the single-case beyond the convective core, while it almost stops on both sides of the above convective shell. Our overshooting mixing scheme is similar to the maximal overshoot scheme of Constantino et al. (2015). In the final stage, continuous injection of fresh helium into the convective core by the overshooting mixing happens, which is similar to the"core breathing pulses" (Sweigart & Demarque 1973;Castellani et al. 1985). Copyright © 2018, The Authors. All rights reserved.

关键词： Mixing

来源：评论

学校读者我要写书评

暂无评论

Science objectives of the Einstein Probe mission

arXiv

引用

arXiv 2025年

作者： Yuan, Weimin Dai, Lixin Feng, Hua Jin, Chichuan Jonker, Peter Kuulkers, Erik Liu, Yuan Nandra, Kirpal O’Brien, Paul Piro, Luigi Rau, Arne Rea, Nanda Sanders, Jeremy Tao, Lian Wang, Junfeng Wu, Xuefeng Zhang, Bing Zhang, Shuangnan Ai, Shunke Buchner, Johannes Bulbul, Esra Chen, Hechao Chen, Minghua Chen, Yong Chen, Yu-Peng Coleiro, Alexis Zelati, Francesco Coti Dai, Zigao Fan, Xilong Fan, Zhou Friedrich, Susanne Gao, He Ge, Chong Ge, Mingyu Geng, Jinjun Ghirlanda, Giancarlo Gianfagna, Giulia Gou, Lijun Guillot, Sébastien Hou, Xian Hu, Jingwei Huang, Yongfeng Ji, Long Jia, Shumei Komossa, S. Kong, Albert K.H. Lan, Lin Li, An Li, Ang Li, Chengkui Li, Dongyue Li, Jian Li, Zhaosheng Ling, Zhixing Liu, Ang Liu, Jinzhong Liu, Liangduan Liu, Zhu Luo, Jiawei Ma, Ruican Maggi, Pierre Maitra, Chandreyee Marino, Alessio Ng, Stephen Chi-Yung Pan, Haiwu Rukdee, Surangkhana Soria, Roberto Sun, Hui Tam, Pak-Hin Thomas Thakur, Aishwarya Linesh Tian, Hui Troja, Eleonora Wang, Wei Wang, Xiangyu Wang, Yanan Wei, Junjie Wen, Sixiang Wu, Jianfeng Wu, Ting Xiao, Di Xu, Dong Xu, Renxin Xu, Yanjun Xu, Yu Yang, Haonan You, Bei Yu, Heng Yu, Yunwei Zhang, Binbin Zhang, Chen Zhang, Guobao Zhang, Liang Zhang, Wenda Zhang, Yu Zhou, Ping Zou, Zecheng National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China School of Astronomy and Space Sciences University of Chinese Academy of Sciences Beijing100049 China Department of Physics University of Hong Kong Pokfulam Road Hong Kong Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Department of Astrophysics IMAPP Radboud University Nijmegen6500 GL Netherlands SRON Netherlands Institute for Space Research Leiden 2333 CA Netherlands ESA/ESTEC Noordwijk 2201 AZ Netherlands Max Planck Institute for Extraterrestrial Physics Garching85748 Germany School of Physics and Astronomy University of Leicester LeicesterLE1 7RH United Kingdom INAF - Istituto di Astrofisica e Planetologia Spaziali Rome00133 Italy CSIC Campus UAB BarcelonaE-08193 Spain BarcelonaE-08034 Spain Department of Astronomy Xiamen University Fujian Xiamen361005 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing210023 China School of Astronomy and Space Sciences University of Science and Technology of China Hefei230026 China Nevada Center for Astrophysics University of Nevada Las Vegas NV89154 United States Department of Physics and Astronomy University of Nevada Las Vegas NV89154 United States Department of Astronomy School of Physics and Technology Wuhan University Wuhan430072 China School of Physics and Astronomy Yunnan University Kunming650500 China Xinjiang Astronomical Observatory Chinese Academy of Sciences Urumqi830011 China Université Paris Cité CNRS Astroparticule et Cosmologie ParisF-75013 France Department of Astronomy University of Science and Technology of China Hefei230026 China Institute for Frontier in Astronomy and Astrophysics Beijing Normal University Beijing102206 China Department of Astronomy Beijing Normal University Beijing100875 China INAF – Osservatorio Astronomico di Brera LC MerateI-23807 Italy INFN – sezione di Milan

The Einstein Probe (EP) is an interdisciplinary mission of time-domain and X-ray astronomy. Equipped with a wide-field lobster-eye X-ray focusing imager, EP will discover cosmic X-ray transients and monitor the X-ray variability of known sources in 0.5–4 keV, at a combination of detecting sensitivity and cadence that is not accessible to the previous and current wide-field monitoring missions. EP can perform quick characterisation of transients or outbursts with a Wolter-I X-ray telescope onboard. In this paper, the science objectives of the Einstein Probe mission are presented. EP is expected to enlarge the sample of previously known or predicted but rare types of transients with a wide range of timescales. Among them, fast extragalactic transients will be surveyed systematically in soft X-rays, which include γ-ray bursts and their variants, supernova shock breakouts, and the predicted X-ray transients associated with binary neutron star mergers. EP will detect X-ray tidal disruption events and outbursts from active galactic nuclei, possibly at an early phase of the flares for some. EP will monitor the variability and outbursts of X-rays from white dwarfs, neutron stars and black holes in our and neighbouring galaxies at flux levels fainter than those detectable by the current instruments, and is expected to discover new objects. A large sample of stellar X-ray flares will also be detected and characterised. In the era of multi-messenger astronomy, EP has the potential of detecting the possible X-ray counterparts of gravitational wave events, neutrino sources, and ultra-high energy γ-ray and cosmic ray sources. EP is expected to help advance the studies of extreme objects and phenomena revealed in the dynamic X-ray universe, and their underlying physical processes. Besides EP’s strength in time-domain science, its follow-up telescope, with excellent performance, will also enable advances in many areas of X-ray astronomy. © 2025, CC BY-NC-ND.

关键词： Cosmology

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：