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An Initial Analysis of a Strongly Lensed QSO Candidate Identified by LAMOST

Research in Astronomy and Astrophysics 2023年第10期23卷 349-356页

作者： Y.H.Chen M.Y.Tang H.Shu H.Tu Institute of Astrophysics Chuxiong Normal UniversityChuxiong 675000China School of Physics and Electronical Science Chuxiong Normal UniversityChuxiong 675000China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650011China Department of Astronomy Yunnan Universityand Key Laboratory of Astroparticle Physics of Yunnan ProvinceKunming 650091China Physics Department&Shanghai Key Lab for Astrophysics Shanghai Normal UniversityShanghai 200234China

From 2011 to 2021,LAMOST has released a total of 76,167 quasar *** try to search for gravitationally lensed QSOs by limiting coordinate differences and redshift differences of these *** name,brightness,spectrum,photometry and other information of each QSO will be visually checked *** attention should be paid to check whether there are groups of galaxies,gravitationally lensed arcs,Einstein crosses,or Einstein rings near the *** careful selection,we select LAMOST J160603.01+290050.8(A)and LAMOST J160602.81+290048.7(B)as a candidate and perform an initial *** A and B are336 apart and they display blue during photometric *** redshift values of components A and B are0.2%different,their Gaia_g values are 1.3%different,and their ugriz values are 1.0%or less *** the spectra covering from 3690 to 9100?,the emission lines of C II,Mg,Hγ,OⅢ,and Hβare present for both components A and B and the ratio of flux(B)to flux(A)from LAMOST is basically a constant,around ***,no galaxies have been found between components A and *** et *** them as binary *** we accidentally find a galaxy group near components A and *** the center of dark matter in the galaxy group is at the center between components A and B,components A and B are probably gravitationally lensed *** estimate that the Einstein mass is 1.46×10^(11)M_⊙and the total mass of the lens is1.34×10^(13)M_⊙.The deflection angle is 197 at positions A and B and the velocity dispersion is 261 km s^(-1).Theoretically,this candidate could be a pair of fold images of a strong lensing system by a galaxy group,and we will investigate the possibility when the redshifts of nearby galaxies are available.

关键词： gravitational lensing:strong (galaxies:)quasars:individual(LAMOST J1606+2900) techniques:imaging spectroscopy

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Absolute physical parameters of three poorly studied detached eclipsing binaries

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Research in Astronomy and Astrophysics 2021年第1期21卷 220-228页

作者： Dao-Ye Yang Li-Fang Li Quan-Wang Han Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100012China Key Lab of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 10101China School of Physics and Electronics Qiannan Normal University for NationalitiesDuyun 558000China

The photometric and spectroscopic data for three double-lined detached eclipsing binaries were collected from the photometric and spectral *** light and radial velocity curves of each binary system were simultaneously analyzed using Wilson-Devinney(WD)code,and the absolute physical and orbital parameters of these binaries were *** masses of both components of ASASSN-V J063123.82+192341.9 were found to be M1=1.088±0.016 and M20.883±0.016 M⊙;those of ASAS J011416+0426.4 were determined to be M1=0.934±0.046 and M2=0.754±0.043 M⊙;and those of MW Aur were derived to be M1=2.052±0.196 and M21.939±0.193 M⊙.Finally,the evolutionary status of these detached binaries was discussed based on their absolute parameters and the theoretical stellar models.

关键词： stars:binaries:eclipsing stars:fundamental parameters stars:evolution stars:individual:ASASSN-V J063123.82+192341.9,ASAS J011416+0426.4 and MW Aur

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An initial analysis of a strongly-lensed QSOs candidate identified by LAMOST

arXiv

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arXiv 2023年

作者： Chen, Yanhui H. Tang, M.Y. Shu, H. Tu, H. Institute of Astrophysics Chuxiong Normal University Chuxiong675000 China School of Physics and Electronical Science Chuxiong Normal University Chuxiong675000 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences P.O. Box 110 Kunming650011 China Department of Astronomy Yunnan University Key Laboratory of Astroparticle Physics of Yunnan Province Kunming650091 China Physics Department Shanghai Key Lab for Astrophysics Shanghai Normal University Shanghai200234 China

From 2011 to 2021, LAMOST has released a total of 76,167 quasar data. We try to search for gravitationally lensed QSOs by limiting coordinate differences and redshift differences of these QSOs. The name, brightness, spectrum, photometry and other information of each QSO will be visually checked carefully. Special attention should be paid to check whether there are groups of galaxies, gravitationally lensed arcs, Einstein crosses, or Einstein rings near the QSOs. Through careful selection, we select LAMOST J160603.01+290050.8 (A) and LAMOST J160602.81+290048.7 (B) as a candidate and perform an initial analysis. The component A and B are 3.36 arc seconds apart and they display blue during photometric observations. The redshift values of component A and B are 0.2% different, their Gaia g values are 1.3% different, and their ugriz values are 1.0% or less different. For the spectra covering from 3,690 Å to 9,100 Å, the emission lines of C II, Mg, H γ, O III, and H β are present for both component A and B and the ratio of flux(B) to flux(A) from LAMOST is basically a constant, around 2.2. However, no galaxies have been found between component A and B. Inada et al. identified them as binary quasars. But we accidentally find a galaxy group near the component A and B. If the center of dark matter in the galaxy group is at the center between component A and B, the component A and B are probably gravitationally lensed QSOs. We estimate that the Einstein mass is 1.46 × 1011 M and the total mass of the lens is 1.34 × 1013 M. The deflection angle is 1.97 arc seconds at positions A and B and the velocity dispersion is 261 km s−1. Theoretically, this candidate could be a pair of fold images of a strong lensing system by a galaxy group, and we will investigate the possibility when the redshifts of nearby galaxies are available. Copyright © 2023, The Authors. All rights reserved.

关键词： Galaxies

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Multi-epoch spectroscopy of Mg II broad absorption line transitions

arXiv

引用

arXiv 2021年

作者： Yi, Weimin Timlin, John Yunnan Observatories Kunming650216 China Department of Astronomy & Astrophysics The Pennsylvania State University 525 Davey Lab University ParkPA16802 United States Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming650216 China

Built upon a sample of 134 quasars that was dedicated to a systematic study of Mg ii-BAL variability from Yi et al. (2019a), we investigate these quasars showing Mg ii-BAL disappearance or emergence with the aid of at least three epoch optical spectra sampled more than 15 yr in the observed frame. We identified 3/3 quasars undergoing pristine/tentative BAL transformations. The incidence of pristine BAL transformations in the sample is therefore derived to be 2.2+2−122%, consistent with that of high-ionization BAL transformations from the literature. Adopting an average Mg ii-BAL disappearance timescale of rest-frame 6.89 yr among the six quasars, the average characteristic lifetime of Mg ii BALs in the sample is constrained to be >160 yr along our line of sight. There is a diversity of BAL-profile variability observed in the six quasars, probably reflecting a variety of mechanisms at work. Our investigations of Mg ii-BAL transitions, combined with observational studies of BAL transitions from the literature, imply an overall FeLoBAL/LoBAL→HiBAL/non-BAL transformation sequence along with a decrease in reddening. This sequence is consistent with the evacuation models for the origin of commonly seen blue quasars, in which LoBAL quasars are in a shorted-lived, blowout phase. © 2021, CC BY-NC-SA.

关键词： Galaxies

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The 2175 Ã bump features in FeLoBAL quasars: One indicator of MW-like dust in the nuclear region of quasars

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Astronomy and Astrophysics 2022年 663卷

作者： Zhang, Shaohua Ge, Jian Ji, Tuo Jiang, Peng Luo, Zhijian Pan, Xiang Shi, Xiheng Shu, Chenggang Wang, Jianguo Xiao, Hubing Zhou, Hongyan Shanghai Key Lab For Astrophysics Shanghai Normal University Shanghai200234 China Key Laboratory For Research In Galaxies And Cosmology Shanghai Astronomical Observatory Chinese Academy Of Sciences Shanghai200030 China Key Laboratory Of Polar Science Polar Research Institute Of China Ministry Of Natural Resources Shanghai200136 China Key Laboratory For The Structure And Evolution Of Celestial Objects Yunnan Observatories Chinese Academy Of Sciences Kunming Yunnan650011 China Key Laboratory For Research In Galaxies And Cosmology Department Of Astronomy University Of Science And Technology Of China Chinese Academy Of Sciences Hefei Anhui230026 China School Of Astronomy And Space Science University Of Science And Technology Of China Hefei Anhui230026 China

To investigate the properties of dust in the nuclear region of quasars, we explored the extinction curves of the iron low-ionisation broad absorption line (FeLoBAL) quasar SDSS J163004.29+311957.6 and its two analogues. The parametrised extinction curves indicated the Milky Way-like 2175 Ã bump features in underlying extinction, which are similar to those seen in the Local Group and in a subset of high-redshift star-forming galaxies. Compared to the bump features in the Large Magellanic Cloud (LMC), the detections in this work are much closer to those in the Milky Way (MW). These bump features, as well as those in the high-and low-ionisation broad absorption line (BAL) quasars with 2175 Ã bumps, are probably the counterpart of the 2175 Ã bump features in the quasar environment. This type of dust grain is generally small, easily disrupted by high-energy photons, and has difficulty surviving in the radiation field of the active galactic nucleus. However, due to the presence of absorption-line outflows, the 2175 Ã bump feature in quasars, which should be rare, is seen many times in BAL quasars. The shielding effect of outflow clouds allows the MW-like dust grains to be assembled or extends the survival period in the quasar nuclear region. The process and physical and chemical conditions deserve further observational study and investigation. © 2022 ESO.

关键词： Dust

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The Common Envelope evolution Outcome. II. Short Orbital Period Hot Subdwarf B Binaries Reveal a Clear Picture

arXiv

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arXiv 2023年

作者： Ge, Hongwei Tout, Christopher A. Webbink, Ronald F. Chen, Xuefei Sarkar, Arnab Li, Jiao Li, Zhenwei Zhang, Lifu Han, Zhanwen Yunnan Observatories Chinese Academy of Sciences 396 YangFangWang Guandu District Kunming650216 China Key Laboratory for Structure and Evolution of Celestial Objects Chinese Academy of Sciences P.O. Box 110 Kunming650216 China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China Institute of Astronomy The Observatories University of Cambridge Madingley Road CambridgeCB3 0HA United Kingdom University of Illinois at Urbana-Champaign 1002 W Green St Urbana61801 United States Key Lab of Space Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China

Common envelope evolution (CEE) is vital to form short orbital period compact binaries. It covers many objects, such as double compact merging binaries, type Ia supernovae progenitors, binary pulsars and X-ray binaries. Knowledge of the common envelope (CE) ejection efficiency still needs to be improved, though progress has been made recently. Short orbital period hot subdwarf B star (sdB) plus white dwarf (WD) binaries are the most straightforward samples with which to constrain CEE physics. We apply the known orbital period–white dwarf mass relation to constrain the sdB progenitors of seven sdB+WD binaries with a known inclination angle. The average CE efficiency parameter is 0.32. This is consistent with previous studies. However, the CE efficiency need not be constant but a function of the initial mass ratio based on well-constrained sdB progenitor mass and evolutionary stage. Our results can be used as physical inputs for binary population synthesis simulations of related objects. A similar method can also be applied to study other short orbital period WD binaries. Copyright © 2023, The Authors. All rights reserved.

关键词： White dwarfs

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Mass-Ratio Distribution of Binaries From the LAMOST-MRS Survey

arXiv

引用

arXiv 2022年

作者： Li, Jiangdan Li, Jiao Liu, Chao Li, Chunqian Guo, Yanjun Wang, Luqian Chen, Xuefei Xing, Lifeng Hou, Yonghui Han, Zhanwen 396 Yangfangwang Guandu District Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects CAS Kunming650216 China University of Chinese Academy of Sciences Beijing100049 China Key Lab of Space Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China CAS Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Nanjing Institute of Astronomical Optics & Technology National Astronomical Observatories Chinese Academy of Sciences Nanjing210042 China School of Astronomy and Space Science University of Chinese Academy of Sciences China

Binary evolution leads to the formation of important objects crucial to the development of astrophysics, but the statistical properties of binary populations are still poorly understood. The LAMOST-MRS has provided a large sample of stars to study the properties of binary populations, especially for the mass ratio distributions and the binary fractions. We have devised a Peak Amplitude Ratio (PAR) approach to derive the mass ratio of a binary system based on results obtained from its spectrum. By computing a cross-correlation function (CCF), we established a relationship between the derived mass ratio and the PARs of the binary systems. By utilizing spectral observations obtained from LAMSOT DR6 DR7, we applied the PAR approach to form distributions of the derived mass ratio of the binary systems to the spectral types. We selected the mass ratio within the range of 0.6 − 1.0 for investigating the mass-ratio distribution. Through a power-law fitting, we obtained the power index γ values of −0.42 ±0.27, 0.03 ±0.12, and 2.12 ±0.19 for A-, F-, and G-type stars identified in the sample, respectively. The derived γ-values display an increasing trend toward lower primary star masses, and G-type binaries tend to be more in twins. The close binary fractions (for P 150 d and q 0.6) in our sample for A, F and G binaries are 7.6 ± 0.5%, 4.9 ± 0.2% and 3.7 ± 0.1%, respectively. Note that the PAR approach can be applied to large spectroscopic surveys of stars. Copyright © 2022, The Authors. All rights reserved.

关键词： Surveys

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The 2175 Å~ Bump Features in FeLoBAL Quasars: One Indicator of MW-like Dust in the Nuclear Region of Quasar

arXiv

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arXiv 2022年

作者： Zhang, Shaohua Ge, Jian Ji, Tuo Jiang, Peng Luo, Zhijian Pan, Xiang Shi, Xiheng Shu, Chenggang Wang, Jianguo Xiao, Hubing Zhou, Hongyan Shanghai Key Lab for Astrophysics Shanghai Normal University Shanghai200234 China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai200030 China Key Laboratory of Polar Science Polar Research Institute of China Ministry of Natural Resources Shanghai200136 China Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan Observatories Chinese Academy of Sciences Yunnan Kunming650011 China Key Laboratory for Research in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China Chinese Academy of Sciences Anhui Hefei230026 China School of Astronomy and Space Science University of Science and Technology of China Anhui Hefei230026 China

To investigate the properties of dust in the nuclear region of quasars, we explored the extinction curves of the iron low-ionization broad absorption line (FeLoBAL) quasar SDSS J163004.29+311957.6 and its two analogues. The parameterized extinction curves indicated the Milky Way-like 2175 Å bump features in underlying extinction, which are similar to those seen in the Local Group and a subset of high-redshift star-forming galaxies. Compared to the bump features in the Large Magellanic Clouds (LMC), the detections in this work are much closer to those in the Milky Way (MW). These bump features, as well as those in the high- and low-ionization broad absorption line (BAL) quasars of Zhang et al., are probably the counterpart of the 2175 Å bump features in the quasar environment. This type of dust grain is generally small, easily disrupted by high-energy photons and has difficulty surviving in the radiation field of the active galactic nucleus (AGN). However, due to the presence of absorption-line outflows, the 2175 Å bump feature in quasars, which should be rare, is seen many times in BAL quasars. The shielding effect of outflow clouds allows the MW-like dust grains to be assembled or extends the survival period in the quasar nuclear region. The process, and physical and chemical conditions deserve further observational study and investigation. © 2022, CC BY.

关键词： Dust

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Three new late-type hypervelocity star candidates from Gaia DR2 with refined selection criteria

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Research in Astronomy and Astrophysics 2020年第3期20卷 170-184页

作者： Jiao Li Shi Jia Yan Gao Deng-Kai Jiang Thomas Kupfer Ulrich Heber Chao Liu Xue-Fei Chen Zhan-Wen Han Yunnan observatories Chinese Academy of SciencesKunming 650011China Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan observatoriesChinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacaoChina Kavli Institute for Theoretical Physics University of CaliforniaSanta BarbaraCA 93106USA Department of Physics University of CaliforniaSanta BarbaraCA 93106USA Dr.Remeis-Sternwarte&ECAP University of Erlangen-NurnbergErlangenGermany Key Lab of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

Several dozen hypervelocity star(HVS)candidates have been reported based on the second data release of Gaia(Gaia DR2).However,it has been proven that the radial velocities of some Gaia HVS candidates are not *** this paper,we employ refined astrometric criteria to re-examine Gaia DR2,arriving at a more reliable sample of HVS and high velocity star candidates than those found by previous *** develop a method called Binary Escape Probability Analysis to identify some HVS *** method allows us to work with stars having only two epochs of measured radial *** stars were usually discarded in previous similar studies.A scrutiny of our final results sheds light on selection effects present in our studies,which we propose to be the focus of future *** total,we find three late-type(2 G-type and 1 K-type)HVS and 21 high velocity star candidates,3 and 11 of which are new,*** by their historical trajectories,which we calculate,all three HVS candidates could not have had Galactic center *** monitoring is required to confirm their status.

关键词： stars kinematics and dynamics-evolution-statistics

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A Roche Lobe-filling hot Subdwarf and White Dwarf Binary: possible detection of an ejected common envelope

arXiv

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arXiv 2022年

作者： Li, Jiangdan Onken, Christopher A. Wolf, Christian Németh, Péter Bessell, Mike Li, Zhenwei Zhang, Xiaobin Li, Jiao Wang, Luqian Li, Lifang Luo, Yangping Chen, Hailiang Ji, Kaifan Chen, Xuefei Han, Zhanwen 396 Yangfangwang Guandu District Kunming650011 China Key Laboratory for the Structure and Evolution of Celestial Objects CAS Kunming650011 China University of Chinese Academy of Sciences Beijing100049 China Research School of Astronomy and Astrophysics Australian National University Weston CreekACT2611 Australia Centre for Gravitational Astrophysics Australian National University CanberraACT2600 Australia Astronomical Institute of the Czech Academy of Sciences OndřejovCZ-25165 Czech Republic *** Fő tér 1 Malomsok8533 Hungary Key Laboratory of Optical Astronomy National Astronomical Observatories CAS Beijing100012 China Key Lab of Space Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences Beijing100101 China Department of Astronomy China West Normal University Nanchong637002 China

Binaries consisting of a hot subdwarf star and an accreting white dwarf (WD) are sources of gravitational wave radiation at low frequencies and possible progenitors of type Ia supernovae if the WD mass is large enough. Here, we report the discovery of the third binary known of this kind: it consists of a hot subdwarf O (sdO) star and a WD with an orbital period of 3.495 hours and an orbital shrinkage of 0.1 s in 6 yr. The sdO star overfills its Roche lobe and likely transfers mass to the WD via an accretion disk. From spectroscopy, we obtain an effective temperature of Teff = 54 240 ± 1 840 K and a surface gravity of log g = 4.841 ± 0.108 for the sdO star. From the light curve analysis, we obtain a sdO mass of MsdO = 0.55 M☉ and a mass ratio of q = MWD/MsdO = 0.738 ± 0.001. Also, we estimate that the disk has a radius of ∼ 0.41R☉ and a thickness of ∼ 0.18R☉. The origin of this binary is probably a common envelope ejection channel, where the progenitor of the sdO star is either an RGB star or, more likely, an early AGB star;the sdO star will subsequently evolve into a WD and merge with its WD companion, likely resulting in an R CrB star. The outstanding feature in the spectrum of this object is strong Ca H&K lines, which are blueshifted by ∼200 km/s and likely originate from the recently ejected common envelope, and we estimated that the remnant CE material in the binary system has a density ∼ 6 × 10−10g/cm3 Copyright © 2022, The Authors. All rights reserved.

关键词： White dwarfs

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