检索结果-内蒙古大学图书馆

The Astrophysical Journal 2018年第2期865卷

作者： Zunli Yuan Jiancheng Wang Ming Zhou Longhua Qin Jirong Mao Yunnan Observatories Chinese Academy of Sciences Kunming 650216 People's Republic of China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 People's Republic of China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 People's Republic of China University of Chinese Academy of Sciences Beijing 100049 People's Republic of China

Spectropolarimetry and photometry of the early afterglow of the gamma-ray burst GRB 191221B

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Buckley, David A.H. Bagnulo, S. Britto, R.J. Mao, J. Kann, D.A. Cooper, J. Lipunov, V. Hewitt, D.M. Razzaque, S. Kuin, N.P.M. Monageng, I.M. Covino, S. Jakobsson, P. van der Horst, A.J. Wiersema, K. Böttcher, M. Campana, S. D'Elia, V. Gorbovskoy, E.S. Gorbunov, I. Groenewald, D.N. Hartmann, D.H. Kornilov, V.G. Mundell, C.G. Podesta, R. Thomas, J.K. Tyurina, N. Vlasenko, D. van Soelen, B. Xu, D. South African Astronomical Observatory PO Box 9 Observatory Road Observatory Cape Town7935 South Africa Department of Astronomy University of Cape Town Private Bag X3 Rondebosch7701 South Africa Armagh Observatory & Planetarium College Hill ArmaghBT61 9DG United Kingdom Department of Physics University of the Free State PO Box 339 Bloemfontein9300 South Africa Yunnan Observatories Chinese Academy of Sciences Yunnan Province Kunming650011 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 Kunming650011 China Glorieta de la Astronomía s/n Granada18008 Spain M. V. Lomonosov Moscow State University SAI Physics Department 13 Univeristetskij pr-t Moscow119991 Russia M.V.Lomonosov Moscow State University Physics Department Leninskie gory GSP-1 Moscow119991 Russia Department of Physics University of Johannesburg PO Box 524 Auckland Park2006 South Africa Mullard Space Science Laboratory Dept. of Space and Climate Sciences University College London Holmbury St Mary DorkingRH5 6NT United Kingdom I-23807 Italy Centre for Astrophysics and Cosmology Science Institute University of Iceland Dunhagi 5 Reykjavík107 Iceland Department of Physics The George Washington University 725 21st St. NW WashingtonDC20052 United States The George Washington University WashingtonDC20052 United States Department of Physics University of Warwick Gibbet Hill Road CoventryCV4 7AL United Kingdom Department of Physics and Astronomy University of Leicester LE1 7RH United Kingdom Centre for Space Research North West University Potchefstroom South Africa ASI-Space Science Data Center via del Politecnico snc Rome00133 Italy INAF - Osservatorio Astronomico di Roma via Frascati 33 Monte Porzio Catone00040 Italy Southern African Large Telescope Foundation PO Box 9 Observatory Road Obse

We report on results of spectropolarimetry of the afterglow of the long gamma-ray burst GRB 191221B, obtained with SALT/RSS and VLT/FORS2, as well as photometry from two telescopes in the MASTER Global Robotic Network, at the MASTER-SAAO (South Africa) and MASTER-OAFA (Argentina) stations. Prompt optical emission was detected by MASTER-SAAO 38 s after the alert, which dimmed from a magnitude (white-light) of ∼ 10 to 16.2 mag over a period of ∼10 ks, followed by a plateau phase lasting ∼10 ks and then a decline to ∼18 mag after 80 ks. The light curve shows complex structure, with four or five distinct breaks in the power-law decline rate. SALT/RSS linear spectropolarimetry of the afterglow began ∼ 2.9 h after the burst, during the early part of the plateau phase of the light curve. Absorption lines seen at ∼ 6010 Å and 5490 Å are identified with the Mg II 2799 Å line from the host galaxy at z = 1.15 and an intervening system located at z = 0.96. The mean linear polarisation measured over 3400 − 8000 Å was ∼1.5% and the mean equatorial position angle (θ) ∼65◦. VLT/FORS2 spectropolarimetry was obtained ∼ 10 h postburst, during a period of slow decline (α = −0.44), and the polarisation was measured to be p = 1.2% and θ = 60◦. Two observations with the MeerKAT radio telescope, taken 30 and 444 days after the GRB trigger, detected radio emission from the host galaxy only. We interpret the light curve and polarisation of this long GRB in terms of a slow-cooling forward-shock. Copyright © 2020, The Authors. All rights reserved.

关键词： Stars

SDSS J012119.10 001949.9:a very short period M dwarf contact binary from SDSS stripe 82

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2015年第12期15卷 2237-2243页

作者： Lin-Qiao Jiang Sheng-Bang Qian Jia Zhang Yunnan Observatories Chinese Academy of Sciences Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of Chinese Academy of Sciences

We present the first multicolor photometric observations of the short period low-mass eclipsing binary SDSS J012119.10-4301949.9. By using the 2013 version of the Wilson-Devinney code, the photometric solutions are derived. It is found that the system is in a contact configuration （f = 18.9± 6.0%） with a moderate mass ratio of 0.5 ± 0.01. A third light contributing about 6.1± 1.3% of the total luminosity in the V band was found, which may come from a cool tertiary component. The derived high orbital inclination （i - 83.9°± 0.5°） and the almost symmetric three light curves suggest that the determined parameters are reliable. Both the color class and spectral class of the system correspond to a spectral type of M0, which may indicate that SDSS J012119.10-001949.9 belongs to a very rare class of M dwarf contact binaries that are below the theoretical short period limit.

关键词： binaries： eclipsing -- stars： individual （SDSS J012119.10-001949.9） --techniques： photometric

SN 2016X: A type ii-p supernova with a signature of shock breakout from explosion of a massive red supergiant

学校读者我要写书评

暂无评论

arXiv 2018年

作者： Huang, F. Wang, X.-F. Hosseinzadeh, G. Brown, P.J. Mo, J. Zhang, J.-J. Zhang, K.-C. Zhang, T.-M. Howell, D.-A. Arcavi, I. McCully, C. Valenti, S. Rui, L.-M. Song, H. Xiang, D.-F. Li, W.-X. Lin, H. Wang, L.-F. Physics Department and Tsinghua Centre for Astrophysics Tsinghua University Beijing100084 China Department of Astronomy Shanghai Jiao Tong University Shanghai200240 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650011 China Department of Physics University of California Santa BarbaraCA93106-9530 United States Las Cumbres Observatory 6740 Cortona Dr. Suite 102 GoletaCA93117-5575 United States George P. and Cynthia Woods Mitchell Institute for Fundamental Physics & Astronomy Texas A&M University Department of Physics Astr Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Centre for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100012 China Department of Physics University of California 1 Shields Avenue DavisCA95616-5270 United States

We present extensive ultraviolet (UV) and optical photometry, as well as dense optical spectroscopy for type II Plateau (IIP) supernova SN 2016X that exploded in the nearby (- 15 Mpc) spiral galaxy UGC 08041. The observations span the period from 2 to 180 days after the explosion;in particular, the Swift UV data probably captured the signature of shock breakout associated with the explosion of SN 2016X. It shows very strong UV emission during the first week after explosion, with contribution of - 20 – 30% to the bolometric luminosity (versus . 15% for normal SNe IIP). Moreover, we found that this supernova has an unusually long rise time of about 12.6 ± 0.5 days in the R band (versus - 7.0 days for typical SNe IIP). The optical light curves and spectral evolution are quite similar to the fast-declining type IIP object SN 2013ej, except that SN 2016X has a relatively brighter tail. Based on the evolution of photospheric temperature as inferred from the Swift data in the early phase, we derive that the progenitor of SN 2016X has a radius of about 930 ± 70 R. This large-size star is expected to be a red supergiant star with an initial mass of & 19 – 20 M based on the mass −− radius relation of the Galactic red supergiants, and it represents one of the most largest and massive progenitors found for SNe IIP. Copyright © 2018, The Authors. All rights reserved.

关键词： Supernovae

A wide star-black-hole binary system from radial-velocity measurements

学校读者我要写书评

暂无评论

arXiv 2019年

作者： Liu, Jifeng Zhang, Haotong Howard, Andrew W. Bai, Zhongrui Lu, Youjun Soria, Roberto Justham, Stephen Li, Xiangdong Zheng, Zheng Wang, Tinggui Belczynski, Krzysztof Casares, Jorge Zhang, Wei Yuan, Hailong Dong, Yiqiao Lei, Yajuan Isaacson, Howard Wang, Song Bai, Yu Shao, Yong Gao, Qing Wang, Yilun Niu, Zexi Cui, Kaiming Zheng, Chuanjie Mu, Xiaoyong Zhang, Lan Wang, Wei Heger, Alexander Qi, Zhaoxiang Liao, Shilong Lattanzi, Mario Gu, Wei-Min Wang, Junfeng Wu, Jianfeng Shao, Lijing Shen, Rongfeng Wang, Xiaofeng Bregman, Joel Stefano, Rosanne Di Liu, Qingzhong Han, Zhanwen Zhang, Tianmeng Wang, Huijuan Ren, Juanjuan Zhang, Junbo Zhang, Jujia Wang, Xiaoli Cabrera-Lavers, Antonio Corradi, Romano Rebolo, Rafael Zhao, Yongheng Zhao, Gang Chu, Yaoquan Cui, Xiangqun Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing China School of Astronomy and Space Sciences University of Chinese Academy of Sciences Beijing China WHU-NAOC Joint Center for Astronomy Wuhan University Wuhan China Department of Astronomy Caltech PasadenaCA United States Sydney Institute for Astronomy School of Physics A28 University of Sydney SydneyNSW Australia The Anton Pannekoek Institute for Astronomy University of Amsterdam Amsterdam Netherlands School of Astronomy and Space Science Nanjing University Nanjing China Misnistry of Education Nanjing China Department of Physics and Astronomy University of Utah Salt Lake CityUT United States CAS Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Hefei China Nicolaus Copernicus Astronomical Centre Polish Academy of Sciences Warsaw Poland Instituto de Astrofísica de Canarias La Laguna Tenerife Spain Departamento de Astrofsica Universidad de La Laguna Santa Cruz de Tenerife Spain Astronomy Department University of California BerkeleyCA United States School of Physics and Technology Wuhan University Wuhan China Monash Centre for Astrophysics School of Physics and Astronomy Monash University 19 Rainforest Walk VIC Australia Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China INAF–Osservatorio Astrofisico di Torino Pino Torinese Italy Department of Astronomy Xiamen University Xiamen China Kavli Institute for Astronomy and Astrophysics Peking University Beijing China School of Physics and Astronomy Sun Yat-Sen University Zhuhai China Physics Department and Tsinghua Center for Astrophysics Tsinghua University Beijing China Department of Astronomy University of Michigan 1085 South University Street Ann ArborMI United States Harvard-Smithsonian Center for Astrophysics CambridgeMA United States Key Laboratory of Dark Matter and Space Astr

All stellar mass black holes have hitherto been identified by X-rays emitted by gas that is accreting onto the black hole from a companion star. These systems are all binaries with black holes below 30 M*1–4. Theory predicts, however, that X-ray emitting systems form a minority of the total population of star-black hole binaries5,6. When the black hole is not accreting gas, it can be found through radial velocity measurements of the motion of the companion star. Here we report radial velocity measurements of a Galactic star, LB-1, which is a B-type star, taken over two years. We find that the motion of the B-star and an accompanying Hα emission line require the presence of a dark companion with a mass of 68+11−13 M*, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. The gravitational wave experiments have detected similarly massive black holes7, 8, but forming such massive ones in a high-metallicity environment would be extremely challenging to current stellar evolution theories9–11. Copyright © 2019, The Authors. All rights reserved.

关键词： Stars

Multi-color light curves and orbital period research of eclipsing binary V1073 Cyg

学校读者我要写书评

暂无评论

arXiv 2017年

作者： Tian, Xiao-man Zhu, Li-ying Qian, Sheng-bang Li, Lin-jia Jiang, Lin-qiao P. O. Box 110 Kunming650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P. O. Box 110 Kunming650216 China University of the Chinese Academy of Science Yuquan Road 19 Sijingshang Block Beijing100049 China School of Physics and Electronic Engineering Sichuan University of Science & Engineering Zigong643000 China

New Multi-color B V Rc Ic photometric observation are presented for W UMa type eclipsing binary V1073 Cyg. The multi-color light curves analysis with the Wilson-Devinney(W-D) procedure acquired the absolute parameters of this system, showing that V1073Cyg is a shallow contact binary system with fill-out factor f = 0.124(±0.011). We collected all available times of light minima spanning 119 years including CCD data to construct the O-C curve and made detailed O-C analysis. The O-C diagram shows that the period change is complex. There exist a long-term continuous decrease and a cyclic variation. The period is decreasing at a rate of P = −1.04(±0.18) × 10−10days · cycle−1, and with the period decrease, V1073 Cyg will evolve to deep contact stage. The cyclic variation with a period of P3 = 82.7(±3.6)years and an amplitude of A = 0.028(±0.002)day may be explained by the magnetic activity of one or both components or the light travel time effect (LTTE) caused by a distant third companion with M3(i′ = 90◦) = 0.511M. Copyright © 2017, The Authors. All rights reserved.

关键词： Stars

Kerr-Newman-AdS black hole in quintessential dark energy

学校读者我要写书评

暂无评论

Physical Review D 2017年第6期95卷 064015-064015页

作者： Zhaoyi Xu Jiancheng Wang Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming 650216 People’s Republic of China University of Chinese Academy of Sciences Beijing 100049 People’s Republic of China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming 650216 People’s Republic of China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing 100012 People’s Republic of China

Quintessential dark energy with pressure p and density ρ is related by equation of state p=ωρ with the state parameter −1<ω<−1/3. The cosmological dark energy influence on black hole spacetime is interesting and important. In this paper, we study the Kerr-Newman-AdS solutions of the Einstein-Maxwell equation in quintessence field around a black hole by Newman-Janis algorithm and complex computations. From the horizon structure equation, we obtain the expression between quintessence parameter α and cosmological constant Λ if the black hole exists two cosmological horizon rq and rc when ω=−2/3, the result is different from rotational black hole in quintessence matter situation. Through analysis we find that the black hole charge cannot change the value of α. But the black hole spin and cosmological constant are opposite. The black hole spin and cosmological constant make the maximum value of α small. The existence of four horizon leads seven types of extremal black holes to constrain the parameter α. With the state parameter ω ranging from −1 to −1/3, the maximum value of α changes from Λ to 1. When ω→−1, the quintessential dark energy likes cosmological constant. The singularity of the black holes is the same with that of Kerr black hole. We also discuss the rotation velocity of the black holes on the equatorial plane for ω=−2/3, −1/2 and −1/3. For small value of α, the rotation velocity on the equatorial plane is asymptotically flat and it can explain the rotation curves in spiral galaxies.

关键词： Dark energy General relativity

The role of environment on the star formation history of disc galaxies

学校读者我要写书评

暂无评论

arXiv 2017年

作者： Kang, Xiaoyu Zhang, Fenghui Chang, Ruixiang Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China

NGC 2403, NGC 300 and M33 are three nearby pure-disc galaxies with similar stellar mass in different environments, they are benchmarks for understanding late-type spiral galaxies in different environments. The chemical evolution and growth of their discs are investigated by using the simple chemical evolution model, in which their discs are assumed to originate and grow through the accretion of the primordial gas, and the gas outflow process is also taken into account. Through comparative study of the best-fitting model predicted star formation histories for them, we hope to derive a picture of the local environment on the evolution and star formation histories of galaxies and whether or not the isolated galaxies follow similar evolution history. Our results show that these three galaxies accumulated more than 50 percent of their stellar mass at z 25−1. The similar metallicity gradients in NGC 2403 and NGC 300 indicate that they may experience similar chemical evolutionary histories. The principal epoch of star formation on the discs of NGC 2403 and NGC 300 is earlier than that on the disc of M33, and the mean age of stellar populations along the discs of both NGC 2403 and NGC 300 is older than that of M33. Our results indicates that the evolution and star formation history of a galaxy indeed depends on its local environment, at least for galaxies with stellar mass of 109.2 M ∼ 109.7 M. Copyright © 2017, The Authors. All rights reserved.

关键词： Galaxies

Long-term photometric behaviour of the eclipsing Z Cam-type dwarf nova AY Psc

学校读者我要写书评

暂无评论

arXiv 2017年

作者： Han, Zhong-Tao Qian, Sheng-Bang Voloshina, Irina Zhu, Li-Ying 7 P. O. Box 110 Kunming650216 China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P. O. Box 110 Kunming650216 China University of Chinese Academy of Sciences Yuquan Road 19# Sijingshang Block Beijing100049 China Sternberg Astronomical Institute Moscow State University Universitetskij prospect 13 Moscow119992 Russia

New eclipse timings of the Z Cam-type dwarf nova AY Psc were measured and the orbital ephemeris was revised. Based on the long-term AAVSO data, moreover, the outburst behaviors were also explored. Our analysis suggests that the normal outbursts are quasiperiodic, with an amplitude of ~ 2.5(±0.1) mag and a period of ~ 18.3(±0.7) days. The amplitude vs. recurrence-time relation of AY Psc is discussed, and we concluded that this relation may represents general properties of dwarf nova (DN) outbursts. The observed standstill ends with an outburst, which is inconsistent with the general picture of Z Cam-type stars. This unusual behavior was considered to be related to the mass-transfer outbursts. Moreover, the average luminosity is brighter during standstills than during outburst cycles. The changes in brightness marks the variations in M2due to the disc of AY Psc is nearly steady state.M2value was limited to the range from 6.35 × 10-9to 1.18 × 10-8Moyr-1. More detailed examination shows that there are a few small outbursts presence during standstills. These events with amplitudes of ~ 0.5 - 0.9 mag are very similar to the stunted outbursts reported in some *** discussed several possible mechanisms and suggested that the most reasonable mechanism for these stunted outbursts is a changing mass-transfer rate. Copyright © 2017, The Authors. All rights reserved.

关键词： Cams

Discovery of two new hypervelocity stars from the lamost spectroscopic surveys

学校读者我要写书评

暂无评论

arXiv 2017年

作者： Huang, Y. Liu, X.-W. Zhang, H.-W. Chen, B.-Q. Xiang, M.-S. Wang, C. Yuan, H.-B. Tian, Z.-J. Li, Y.-B. Wang, B. South-Western Institute for Astronomy Research Yunnan University Kunming650500 China Department of Astronomy Peking University Beijing100871 China Kavli Institute for Astronomy and Astrophysics Peking University Beijing100871 China Department of Astronomy Beijing Normal University Beijing100875 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100012 China Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories CAS Kunming650216 China LAMOST Fellow

We report the discovery of two new unbound hypervelocity stars (HVSs) from the LAMOST spectroscopic surveys. They are respectively a B2V type star of ∼ 7 Mowith a Galactic rest-frame radial velocity of 502 km s-1at a Galactocentric radius of ∼ 21 kpc and a B7V type star of ∼ 4 Mowith a Galactic rest-frame radial velocity of 408 km s-1at a Galactocentric radius of ∼ 30 kpc. The origins of the two HVSs are not clear given their currently poorly measured proper motions. However, the future data releases of Gaia should provide proper motion measurements accurate enough to solve this problem. The ongoing LAMOST spectroscopic surveys are expected to yield more HVSs to form a statistical sample, providing vital constraint on understanding the nature of HVSs and their ejection mechanisms. Copyright © 2017, The Authors. All rights reserved.

关键词： Stars