The Binarity of Early-type Stars from LAMOST medium-resolution Spectroscopic Survey  

作　　者：Yanjun Guo Jiao Li Jianping Xiong Jiangdan Li Luqian Wang Heran Xiong Feng Luo Yonghui Hou Chao Liu Zhanwen Han Xuefei Chen 

机构地区：[1]Yunnan Observatories,Chinese Academy of Sciences,P.O.Box 110,Kunming,650011,China [2]School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing,100049,China [3]Key Laboratory of Space Astronomy and Technology,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [4]Research School of Astronomy and Astrophysics,Mount Stromlo Observatory,The Australian National University,ACT 2611,Australia [5]Nanjing Institute of Astronomical Optics&Technology,National Astronomical Observatories,Chinese Academy of Sciences,Nanjing 210042,China [6]School of Astronomy and Space Science,University of Chinese Academy of Sciences,China [7]Center for Astronomical Mega-Science,Chinese Academy of Sciences,Beijing 100012,China

出　　处：《Research in Astronomy and Astrophysics》2022年第2期92-107,共16页天文和天体物理学研究（英文版）

基　　金：supported by the Natural Science Foundation of China(NSFC,Grant Nos.11733008,12090040,12090043,11521303,12125303);Yunnan Province and the National Tenthousand Talents Program;National Key R&D Program of China No.2019YFA0405500;the NSFC with Grant No.11835057;The Guoshoujing Telescope(the Large Sky Area MultiObject Fiber Spectroscopic Telescope,LAMOST)is a National Major Scientific Project built by the Chinese Academy of Sciences;Funding for the project has been provided by the National Development and Reform Commission;LAMOST is operated and managed by the National Astronomical Observatories,Chinese Academy of Sciences;supported by the Key Research Program of Frontier Sciences,CAS,Grant No.QYZDY-SSW-SLH007;the science research grants from the China Manned Space Project with No.CMS-CSST-2021-A10。

摘　　要：Massive binaries play significant roles in many fields.Identifying massive stars,particularly massive binaries,is of great importance.In this paper,by adopting the technique of measuring the equivalent widths of several spectral lines,we identified 9382 early-type stars from the LAMOST medium-resolution survey and divided the sample into four groups,T1(~O-B4),T2(~B5),T3(~B7)and T4(~B8-A).The relative radial velocities RVrelwere calculated using Maximum Likelihood Estimation.The stars with significant changes of RVreland at least larger than 15.57 km s-1 were identified as spectroscopic binaries.We found that the observed spectroscopic binary fractions for the four groups are 24.6%±0.5%,20.8%±0.6%,13.7%±0.3%and 7.4%±0.3%,respectively.Assuming that orbital period(P)and mass ratio(q)have intrinsic distributions as f(P)∝Pπ(1<P<1000 days)and f(q)∝qκ(0.1<q<1),respectively,we conducted a series of Monte-Carlo simulations to correct observational biases for estimating the intrinsic multiplicity properties.The results show that the intrinsic binary fractions for the four groups are 68%±8%,52%±3%,44%±6%and 44%±6%,respectively.The best estimated values forπare-1±0.1,-1.1±0.05,-1.1±0.1 and-0.6±0.05,respectively.Theκcannot be constrained for groups T1 and T2 and is-2.4±0.3 for group T3 and-1.6±0.3 for group T4.We confirmed the relationship of a decreasing trend in binary fractions toward late-type stars.No correlation between the spectral type and orbital period distribution has been found yet,possibly due to the limitation of observational cadence.

关 键 词：EARLY-TYPE stars:statistics (stars:)binaries:spectroscopic catalogs 

分 类 号：P153[天文地球—天文学]