检索结果-内蒙古大学图书馆

Shell helium-burning hot subdwarf B stars as candidates for blue large-amplitude pulsators

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Xiong, H. Casagrande, L. Chen, X. Vos, J. Zhang, X. Justham, S. Li, J. Wu, T. Li, Y. Han, Z. Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming650216 China Research School of Astronomy and Astrophysics The Australian National University CanberraACT2611 Australia 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 Astronomical Institute of the Czech Academy of Sciences OndřejovCZ-25165 Czech Republic Department of Astronomy Beijing Normal University Beijing100875 China School of Astronomy & Space Science University of the Chinese Academy of Sciences Beijing100012 China The Key Laboratory of Optical Astronomy National Astronomical Observatories The Chinese Academy of Sciences Datun Road Beijing100012 China University of Chinese of Academy of Science Yuquan Road 19 Shijingshan Block Beijing100049 China Anton Pannekoek Institute for Astronomy University of Amsterdam Science Park 904 Amsterdam1098XH Netherlands Max Planck Institute for Astrophysics Karl-Schwarzschild-Str. 1 Garching85748 Germany Institute of Theoretical Physics Shanxi University Taiyuan030006 China Key Laboratory of Space Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China

Blue large-amplitude pulsators (BLAPs) are a newly discovered type of variable star. Their typical pulsation periods are on the order of a few tens of minutes, with relatively large amplitudes of 0.2-0.4 mag in optical bands, and their rates of period changes are on the order of 10-7yr-1(both positive and negative). They are extremely rare objects and attempts to explain their origins and internal structures have attracted a great deal of attention. Previous studies have proposed that BLAPs may be pre-white dwarfs, with masses around 0.3Mo, or core-helium-burning stars in the range of ∼ 0.7-1.1Mo. In this work, we use a number of MESA models to compute and explore whether BLAPs could be explained as shell helium-burning subdwarfs type B (SHeB sdBs). The models that best match existing observational constraints have helium core masses in the range of ∼ 0.45-0.5Mo. Our model predicts that the positive rate of period change may evolve to negative. The formation channels for SHeB sdBs involve binary evolution and although the vast majority of BLAPs do not appear to be binaries (with the exception of HD 133729), the observational constraints are still very poor. Motivated by these findings, we explored the Roche lobe overflow channel. Of the 304 binary evolution models we computed, about half of them are able to produce SHeB sdBs in long-period binaries that evade detection from the limited observations that are currently available. Copyright © 2022, The Authors. All rights reserved.

关键词： White dwarfs

A catalogue of potential post common envelope binaries

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Kruckow, Matthias U. Neunteufel, Patrick G. Stefano, Rosanne Di Gao, Yan Kobayashi, Chiaki Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650011 China Max Planck Institut für Astrophysik Karl-Schwarzschild-Straße 1 Garching bei München85748 Germany Harvard-Smithsonian Center for Astrophysics 60 Garden St CambridgeMA02138 United States Institute of Gravitational Wave Astronomy School of Physics and Astronomy University of Birmingham BirminghamB15 2TT United Kingdom Centre for Astrophysics Research School of Physics Astronomy and Mathematics University of Hertfordshire HatfieldAL10 9AB United Kingdom

We present a catalogue containing 839 candidate post common envelope systems. Common envelope evolution is very important in stellar astrophysics, particularly in the context of very compact and short-period binaries, including cataclysmic variables, as progenitors of e.g. supernovae type Ia or mergers of black holes and/or neutron stars. At the same time it is a barely understood process in binary evolution. Due to limitations, since partially remedied, on direct simulation, early investigations were mainly focused on providing analytic prescriptions of the outcome of common envelope evolution. In recent years, detailed hydrodynamical calculations have produced deeper insight into the previously elusive process of envelope ejection. However, a direct link between observations and theory of this relatively short-lived phase in binary evolution has not been forthcoming. Therefore, the main insight to be gained from observations has to be derived from the current state of systems likely to have gone through a common envelope. Here we present an extensive catalogue of such observations as found in the literature. The aim of this paper is to provide a reliable set of data, obtained from observations, to be used in the theoretical modelling of common envelope evolution. In this catalogue, the former common envelope donor star is commonly observed as a white dwarf star or as a hot sub-dwarf star. This catalogue includes period and mass estimates, wherever obtainable. Some binaries are border line cases to allow an investigation of the transition between a common envelope formation and other mass-transfer processes. © 2021, CC BY-NC-ND.

关键词： Mass transfer

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

学校读者我要写书评

暂无评论

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 2023年第3期527卷 6473-6494页

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 Gutierrez, 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 D-60438 Frankfurt am Main Germany INAF – Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5 I-35122 Padova Italy INAF – Osservatorio Astronomico d’Abruzzo via M. Maggini snc I-64100 Teramo Italy The Oskar Klein Centre Department of Astronomy Stockholm University AlbaNova SE-10691 Stockholm Sweden Dipartimento di Fisica e Astronomia ‘G. Galilei’ Università di Padova Vicolo dell’Osservatorio 3 I-35122 Padova Italy Department of Applied Physics School of Engineering University of Cádiz Campus of Puerto Real E-11519 Cádiz Spain Instituto de Astrofisíca de Canarias E-38200 La Laguna Tenerife Canary Islands Spain GRANTECAN: Cuesta de San José s/n E-38712 Breña Baja La Palma Spain Institute of Space Sciences (ICE CSIC) Campus UAB Carrer de Can Magrans s/n E-08193 Barcelona Spain Physics Department and Tsinghua Center for Astrophysics (THCA) Tsinghua University Beijing 100084 China Beijing Planetarium Beijing Academy of Science and Technology Beijing 100044 China Astrophysics Research Institute Liverpool John Moores University Liverpool L3 5RF UK Max-Planck-Institut für Astrophysik Karl-Schwarzschild Str.1 D-85748 Garching Germany INFN – Sezione di Padova Via Francesco Marzolo 8 I-35131 Padova Italy Yunnan Observatories Chinese Academy of Sciences Kunming 650216 P. R. China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 P. R. China International Centre of Supernovae Yunnan Key Laboratory Kunming 650216 P. R. China UCD School of Physics L.M.I. Main Building Beech Hill Road Dublin 4 D04 P7W1 Ireland Institut d’Estudis Espacials de Catalunya (IEEC) Gran Capità 2-4 Edifici Nexus Desp. 201 E-08034 Barcelona Spain Institute of Space Sciences (ICE CSIC) Campus UAB Carrer de Can Magrans s/n E-08193 Barcelona Spain Department of Physics and Astronomy Aarhus University Ny Munkegade 120 DK-8000 Aarhus C Den

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 spin-down radiation of a millisecond magnetar with a magnetic field B similar or equal to 6 x 10(14)G could boost the luminosity of SN 2019neq.

关键词： supernovae: general supernovae: individual: SN 2019neq

Searching for multiple populations in star clusters using the China Space Station Telescope

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Li, Chengyuan Zheng, Zhenya Li, Xiaodong Pang, Xiaoying Tang, Baitian Milone, Antonino P. Wang, Yue Wang, Haifeng Jiang, Dengkai School of Physics and Astronomy Sun Yat-sen University Daxue Road Guangdong Zhuhai519082 China CSST Science Center for the Guangdong-Hong Kong-Macau Greater Bay Area Zhuhai519082 China CAS Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Shanghai200030 China Division of Optical Astronomical Technologies Shanghai Astronomical Observatory Shanghai200030 China Department of Physics Xi'an Jiaotong-Liverpool University 111 Ren'ai Road Jiangsu Suzhou215123 China Shanghai Key Laboratory for Astrophysics Shanghai Normal University 100 Guilin Road Shanghai200234 China Dipartimento di Fisica e Astronomia 'Galileo Galilei' Universita di Padova Vicolo dell'Osservatorio 3 PaduaI-35122 Italy Istituto Nazionale di Astrofisica Osservatorio Astronomico di Padova Vicolo dell'Osservatorio 5 PaduaIT-35122 Italy Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China GEPI Observatoire de Paris Université PSL CNRS Place Jules Janssen Meudon92195 France 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 Kunming650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing100012 China

Multiple stellar populations (MPs) in most star clusters older than 2 Gyr, as seen by lots of spectroscopic and photometric studies, have led to a significant challenge to the traditional view of star formation. In this field, space-based instruments, in particular the Hubble Space Telescope (HST), have made a breakthrough as they significantly improved the efficiency of detecting MPs in crowding stellar fields by images. The China Space Station Telescope (CSST) and the HST are sensitive to a similar wavelength interval, but it covers a field of view which is about 5-8 times wider than that of HST. One of its instruments, the Multi-Channel Imager (MCI), will have multiple filters covering a wide wavelength range from NUV to NIR, making the CSST a potentially powerful tool for studying MPs in clusters. In this work, we evaluate the efficiency of the designed filters for the MCI/CSST in revealing MPs in different color-magnitude diagrams (CMDs). We find that CMDs made with MCI/CSST photometry in appropriate UV filters are powerful tools to disentangle stellar populations with different abundances of He, C, N, O and Mg. On the contrary, the traditional CMDs are blind to multiple populations in globular clusters (GCs). We show that CSST has the potential of being the spearhead instrument for investigating MPs in GCs in the next decades. Copyright © 2022, The Authors. All rights reserved.

关键词： Space stations

Deep HI Mapping of Stephan’s Quintet and Its Neighborhood

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Cheng, Cheng Xu, Cong Kevin Appleton, P.N. Duc, P.-A. Tang, N.-Y. Dai, Y.S. Huang, J.-S. Lisenfeld, U. Renaud, F. He, Chuan Feng, Hai-Cheng Chinese Academy of Sciences South America Center for Astronomy National Astronomical Observatories CAS Beijing100101 China National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100101 China CAS Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Caltech/IPAC MC 6-313 1200 E. California Blvd. PasadenaCA91125 United States Université de Strasbourg CNRS Observatoire astronomique de Strasbourg UMR 7550 StrasbourgF-67000 France Department of Astronomy University of Massachusetts AmherstMA01003 United States Center for Astrophysics Harvard & Smithsonian 60 Garden St. CambridgeMA02138 United States Dept. Física Teórica y del Cosmos Campus de Fuentenueva Edificio Mecenas Universidad de Granada GranadaE-18071 Spain Instituto Carlos I de Física Tórica y Computacional Facultad de Ciencias GranadaE-18071 Spain Department of Astronomy and Theoretical Physics Lund Observatory Box 43 LundSE-221 00 Sweden Yunnan Observatories Chinese Academy of Sciences Yunnan Kunming650011 China University of Chinese Academy of Sciences Beijing100049 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Yunnan Kunming650011 China

We carried out deep mapping observations of the atomic hydrogen (HI) 21 cm line emission in a field centered on the famous galaxy group Stephan’s Quintet (SQ), using the Five-hundred-meter Aperture Spherical Telescope (FAST) equipped with the 19-Beam Receiver. The final data cube reaches an HI column density sensitivity of 5σ = 2.1×1017 cm−2 per 20 km s−1 channel with an angular resolution of 40.0. The discovery of a large diffuse feature of the HI emission in the outskirt of the intragroup medium of SQ was reported in a previous paper (Xu et al. 2022). Here we present a new study of the total HI emission of SQ and the detection of several neighboring galaxies, exploiting the high sensitivity and the large sky coverage of the FAST observations. A total HI mass of MHI = 3.48±0.35×1010 M☉ is found for SQ, which is significantly higher than previous measurements in the literature. This indicates that, contrary to earlier claims, SQ is not HI deficient. The excessive HI gas is mainly found in the velocity ranges of 6200 - 6400 km s−1 and 6800 - 7000 km s−1, which was undetected in previous observations that are less sensitive than ours. Our results suggest that the "missing HI" in compact groups may be hidden in the low-density diffuse neutral gas instead of in the ionized gas. Copyright © 2023, The Authors. All rights reserved.

关键词： Mapping

Bayesian discrimination of the panchromatic spectral energy distribution modelings of galaxies

学校读者我要写书评

暂无评论

Proceedings of the International Astronomical Union 2020年第S341期15卷 143-146页

作者： Yunkun Han Zhanwen Han Lulu Fan Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming 650216 P. R. China email: hanyk@*** Center for Astronomical Mega-Science Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing 100012 P. R. China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming 650216 P. R. China Institute of Space Science Shandong University Weihai 264209 China

Fitting the multi-wavelength spectral energy distributions (SEDs) of galaxies is a widely used technique to extract information about the physical properties of galaxies. However, a major difficulty lies in the numerous uncertainties regarding almost all ingredients of the SED modeling of galaxies. The Bayesian methods provide a consistent conceptual basis for dealing with the problem of inference with many uncertainties. While the Bayesian parameter estimation method have become quite popular in the field of SED fitting of galaxies, the Bayesian model comparison method, which is based on the same Bayes’ rule, is still not widely used in this field. With the application of Bayesian model comparison method in a series of papers, we show that the results obtained with Bayesian model comparison are understandable in the context of stellar/galaxy physics. These results indicate that Bayesian model comparison is a reliable and very powerful method for the SED fitting of galaxies.

关键词： galaxies: fundamental parameters galaxies: stellar content galaxies: statistics

On the polarized absorption lines in gamma-ray burst optical afterglows

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Mao, J. Britto, R.J. Buckley, D.A.H. Covino, S. D’Avanzo, P. Kuin, N.P.M. Yunnan Observatories Chinese Academy of Sciences Kunming Yunnan Province650011 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 Department of Physics University of the Free State P.O. Box 339 Bloemfontein9300 South Africa South African Astronomical Observatory P.O. Box 9 Observatory Road Observatory Cape Town7935 South Africa I-23807 Italy Mullard Space Science Laboratory Department of Space and Climate Sciences University College London Holmbury St. Mary DorkingRH5 6NT United Kingdom

Spectropolarimetric measurements of gamma-ray burst (GRB) optical afterglows contain polarization information for both continuum and absorption lines. Based on the Zeeman effect, an absorption line in a strong magnetic field is polarized and split into a triplet. In this paper, we solve the polarization radiative transfer equations of the absorption lines, and obtain the degree of linear polarization of the absorption lines as a function of the optical depth. In order to effectively measure the degree of linear polarization for the absorption lines, a magnetic field strength of at least 103 G is required. The metal elements that produce the polarized absorption lines should be sufficiently abundant and have large oscillation strengths or Einstein absorption coefficients. We encourage both polarization measurements and high-dispersion observations of the absorption lines in order to detect the triplet structure in early GRB optical afterglows. © 2021, CC BY.

关键词： Magnetic fields

The MBH–M∗ Relation of the Hyperluminous Dust-obscured Quasars up to z ∼ 4

学校读者我要写书评

暂无评论

The Astrophysical Journal 2025年第2期986卷 195-195页

作者： Yibin Luo Lulu Fan Weibin Sun Haoran Yu Yunkun Han Guangwen Chen Mengqiu Huang Yihang Zhang Zheyu Lin Department of Astronomy University of Science and Technology of China Hefei 230026 People’s Republic of China yibinluo@*** llfan@*** School of Astronomy and Space Science University of Science and Technology of China Hefei 230026 People’s Republic of China Deep Space Exploration Laboratory Hefei 230088 People’s Republic of China Yunnan Observatories Chinese Academy of Sciences 396 Yangfangwang Guandu District Kunming 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 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 International Centre of Supernovae Yunnan Key Laboratory Kunming 650216 People’s Republic of China Sub-department of Astrophysics University of Oxford Keble Road Oxford OX1 3RH UK

Hot dust-obscured galaxies (Hot DOGs) are a rare population of hyperluminous dust-obscured quasars discovered by the Wide-field Infrared Survey Explorer (WISE) all-sky survey. The heavy circumnuclear dust obscuration allows only a small amount of scattered light from the obscured quasar to escape, enabling the decomposition of the stellar component from the total flux. The presence of scattered light enables the redshift of the source and the properties of the black hole to be obtained from the Sloan Digital Sky Survey (SDSS) and SDSS-related literature. From WISE and SDSS data, we select 11 hyperluminous Hot DOGs at z = 1.5–3.7 with bolometric luminosities L_bol ≳ 10⁴⁷ erg s⁻¹. We investigate the M_BH–M_⋆ relation in these sources using Bayesian spectral energy distribution fitting or with extra constraints from Hubble Space Telescope image decomposition. Stellar masses are successfully derived for eight Hot DOGs. We find high Eddington ratios λ_Edd in these Hot DOGs, with the median value of 1.05 and the maximum value close to 3. The super-Eddington accretion may be associated with the overdense environments of Hot DOGs. We find no significant differences in the M_BH/M_⋆ of these Hot DOGs compared to the local relation, suggesting that these dust-obscured quasars are the progenitors of massive early-type galaxies. We speculate that the subsequent evolution of Hot DOGs may be significantly influenced by active galactic nucleus feedback and remain on the local relation.

关键词：

A close-in substellar object orbiting the sd OB-type eclipsing-binary system NSVS 14256825

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2019年第9期19卷 129-136页

作者： Li-Ying Zhu Sheng-Bang Qian Eduardo Fernaez Lajus Zhi-Hua Wang Lin-Jia Li Yunnan Observatories Chinese Academy of SciencesKunming650216China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming650216China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing100101China University of Chinese Academy of Sciences Beijing100049China Facultad de Ciencias Astronomicas y Geofisicas Universidad Nacional de La Plata1900La PlataBuenos AiresArgentina Instituto de Astrofisica de La Plata(CCT La Plata C CONICET/UNLP) Paseo del Bosque s/nLa PlataBAB1900FWAArgentina

NSVS 14256825 is the second discovered sdOB+dM eclipsing-binary system with an orbital period of 2.65 h. This special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were derived by different authors because of the insufficient coverage of eclipse timings. Since 2008, we have monitored this binary for about 10 yr using several telescopes and 84 new times of light minimum were obtained with high precision. It is found that the O-C curve has been increasing recently and it shows a cyclic variation with a period of 8.83 yr and an amplitude of 46.31 seconds. The cyclic change cannot be explained by magnetic activity cycles of the red dwarf component because the required energy is much larger than that radiated by this component in one whole period. This cyclic change detected in NSVS 14256825 could be explained by the light-travel time effect via the presence of a third body. The lowest mass of the third body is determined to be 14.15 Mjupwhich is in the transition range between planets and brown dwarfs. The substellar object is orbiting around this evolved binary at an orbital separation of around 3 AU with an eccentricity of 0.12. These results indicate that NSVS 14256825 is the first sdOB-type eclipsing binary consisting of a hierarchical substellar *** detection of a close-in substellar companion to NSVS 14256825 will provide some insights on the formation and evolution of sdOB-type binaries and their companions.

关键词： binaries:close binaries:eclipsing stars:evolution stars:individual(NSVS 14256825)