Radial velocity variability fractions of different types of hot subdwarf stars

doi:10.1051/0004-6361/202451411

YNAO OpenIR > 大样本恒星演化研究组

	Radial velocity variability fractions of different types of hot subdwarf stars
	He RJ(贺锐杰)1,2 ; Meng XC(孟祥存)1,3,4 ; Lei, Zhenxin 5,6; Yan, Huahui 7; Lan SY(兰顺义)1,2
发表期刊	ASTRONOMY & ASTROPHYSICS
	2025-01-09
卷号	693
DOI	10.1051/0004-6361/202451411
产权排序	第1完成单位
收录类别	SCI ; EI
关键词	binaries: close stars: evolution subdwarfs
摘要	Context. It is generally thought that hot subdwarfs are helium-core- or helium-shell-burning objects with extremely thin hydrogen envelopes and that binary interactions are always needed in their formation. Different types of hot subdwarfs may have different origins, which will cause them to present different radial velocity (RV) variability properties. Aims. We plan to study the RV-variability fractions of different types of hot subdwarfs, as well as their distributions in the T-eff - log g diagram. This provides insights into the formation of hot subdwarfs. Methods. The cross-correlation function method was adopted to measure RV variations in 434 hot subdwarfs based on spectra obtained with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Light curves from the Transiting Exoplanet Survey were also used to search for short-period binary hot subdwarfs. Results. Only 6 +/- 4% of our single-lined He-rich hot subdwarfs that only show spectroscopic features of hot subdwarfs are found to be RV variable, which is lower than the fraction of single-lined He-poor sdB stars (31 +/- 3%). Single-lined sdB stars with effective temperatures (T-eff) similar to 25 000-33 000 K show an RV-variability fraction of 34 +/- 5%, while lower RV-variability fractions are observed for single-lined sdB stars cooler than about 25 000 K (11 +/- 4%), single-lined sdB/OB stars with T-eff similar to 33 000-40 000 K and surface gravities similar to 5.7-6.0 (13 +/- 3%), as well as single-lined sdO/B stars with T-eff similar to 45 000-70 000 K (10 +/- 7%). Single-lined hot subdwarfs with T-eff similar to 35 000-45 000 K located above the extreme horizontal branch (EHB) show a similar RV-variability fraction of 34 +/- 9% as single-lined sdB stars at about 25 000-33 000 K. The largest RV-variability fraction of 51 +/- 8% is found in single-lined hot subdwarfs below the canonical EHB. The detected RV-variability fraction of our composite hot subdwarfs with an infrared excess in their spectral energy distributions is 9 +/- 3%, which is lower than that fraction of single-lined hot subdwarfs. Since the average RV uncertainty we measured in the LAMOST spectra is about 7.0 km/s, the lower detected RV-variability fraction for composite hot subdwarfs is expected because the RV amplitudes associated with long-period systems are lower. Conclusions. The results here are generally consistent with the canonical binary evolution channels for forming hot subdwarfs. Most single-lined He-rich hot subdwarfs may form through merger channels, while the stable Roche-lobe overflow channel could play an important role in the formation of composite hot subdwarfs. Single-lined hot subdwarfs with T-eff similar to 35 000-45 000 K located above the EHB may have an evolutionary connection to the sdB stars at about 25 000-33 000 K. The different detected RV-variability fractions for the different subclasses of single-lined hot subdwarfs indicate that their formation channels may differ.
资助项目	National Natural Science Foundation of Chian[12288102]; National Natural Science Foundation of Chian[12333008]; National Natural Science Foundation of China[2021YFA1600403]; National Key R&D Program of China[202401BC070007]; National Key R&D Program of China[202201BC070003]; Yunnan Fundamental Research Projects[202302AN360001]; International Centre of Supernovae, Yunnan Key Laboratory[202305AB350003]; Yunnan Revitalization Talent Support Program Science & Technology Champion Project; China Manned Space Project; Chinese Academy of Sciences (CAMS); Guoshoujing Telescope (the Large Sky Area Multi Object Fiber Spectroscopic Telescope LAMOST); National Development and Reform Commission
项目资助者	National Natural Science Foundation of Chian[12288102, 12333008] ; National Natural Science Foundation of China[2021YFA1600403] ; National Key R&D Program of China[202401BC070007, 202201BC070003] ; Yunnan Fundamental Research Projects[202302AN360001] ; International Centre of Supernovae, Yunnan Key Laboratory[202305AB350003] ; Yunnan Revitalization Talent Support Program Science & Technology Champion Project ; China Manned Space Project ; Chinese Academy of Sciences (CAMS) ; Guoshoujing Telescope (the Large Sky Area Multi Object Fiber Spectroscopic Telescope LAMOST) ; National Development and Reform Commission
语种	英语
学科领域	天文学 ; 恒星与银河系
文章类型	Article
出版者	EDP SCIENCES S A
出版地	17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE
ISSN	0004-6361
URL	查看原文
WOS记录号	WOS:001394488200011
WOS研究方向	Astronomy & Astrophysics
WOS类目	Astronomy & Astrophysics
关键词[WOS]	COMMON ENVELOPE EJECTION ; B-STARS ; GAIA DR2 ; CLOSE BINARY ; SURVIVING COMPANIONS ; SUBLUMINOUS STARS ; KPD 1930+2752 ; SDB-STARS ; IA ; I.
EI入藏号	20250317706518
EI分类号	1301.1.3 - 1302.1.2 - 301 - 804 Chemical Products Generally
引用统计
文献类型	期刊论文
版本	出版稿
条目标识符	http://ir.ynao.ac.cn/handle/114a53/27981
专题	大样本恒星演化研究组中国科学院天体结构与演化重点实验室
作者单位	1.Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011, PR China; 2.University of Chinese Academy of Sciences, Beijing 100049, PR China; 3.Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650216, PR China; 4.International Centre of Supernovae, Yunnan Key Laboratory, Kunming 650216, PR China; 5.Key Laboratory of Stars and Interstellar Medium, Xiangtan University, Xiangtan 411105, PR China; 6.Physics Department, Xiangtan University, Xiangtan 411105, PR China; 7.School of Physics and Astronomy, Sun Yat-sen University, Daxue Road, Zhuhai 519082, PR China
第一作者单位	中国科学院云南天文台
推荐引用方式 GB/T 7714	He RJ,Meng XC,Lei, Zhenxin,et al. Radial velocity variability fractions of different types of hot subdwarf stars[J]. ASTRONOMY & ASTROPHYSICS,2025,693.
APA	贺锐杰,孟祥存,Lei, Zhenxin,Yan, Huahui,&兰顺义.(2025).Radial velocity variability fractions of different types of hot subdwarf stars.ASTRONOMY & ASTROPHYSICS,693.
MLA	贺锐杰,et al."Radial velocity variability fractions of different types of hot subdwarf stars".ASTRONOMY & ASTROPHYSICS 693(2025).

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