HOT SUBDWARF STARS OBSERVED IN LAMOST DR1-ATMOSPHERIC PARAMETERS FROM SINGLE-LINED SPECTRA

	HOT SUBDWARF STARS OBSERVED IN LAMOST DR1-ATMOSPHERIC PARAMETERS FROM SINGLE-LINED SPECTRA
	Luo, Yang-Ping1,2,3 ; Nemeth, Peter 4; Liu, Chao1 ; Deng, Li-Cai1 ; Han, Zhan-Wen 3
刊名	ASTROPHYSICAL JOURNAL
	2016-02-20
卷号	818 期号:2
关键词	catalogs subdwarfs surveys techniques: spectroscopic
英文摘要	We present a catalog of 166 spectroscopically identified hot subdwarf stars from LAMOST DR1, 44 of which show the characteristics of cool companions in their optical spectra. Atmospheric parameters of 122 subdwarf stars with non-composite spectra were measured by fitting the profiles of hydrogen (H) and helium (He) lines with synthetic spectra from non-LTE model atmospheres. Most of the sdB stars scatter near the Extreme Horizontal Branch in the T-eff-log g diagram and two well defined groups can be outlined. A clustering of He-enriched sdO stars appears near T-eff = 45,000 K and log g = 5.8. The sdB population separates into several nearly parallel sequences in the T-eff-He abundance diagram with clumps corresponding to those in the T-eff-log g diagram. Over 38,000 K (sdO) stars show abundance extremes; they are either He-rich or He-deficient and we observe only a few stars in the abundance range -1< log y < 0. With increasing temperature these extremes become less prominent and the He abundance approaches log y similar to-0.5. A unique property of our sample is that it covers a large range in apparent magnitude and galactic latitude, therefore it contains a mix of stars from different populations and galactic environments. Our results are consistent with the findings of Hirsch and we conclude that He-rich and He-deficient sdB stars (log y <. 1) probably originate from different populations. We also find that most sdO and sdB stars lie in a narrow strip in the plane of luminosity and helium abundance, which suggests that these atmospheric parameters are correlated.
收录类别	SCI
语种	英语
WOS记录号	WOS:000372302800101
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/5414]
专题	国家天文台_光学天文研究部
作者单位	1.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 2.China West Normal Univ, Sch Phys & Space Sci, Nanchong 637009, Peoples R China 3.Chinese Acad Sci, Key Lab Struct & Evolut Celestial Objects, Kunming 650011, Peoples R China 4.Univ Erlangen Nurnberg, Dr Remeis Sternwarte Astron Inst, D-96049 Bamberg, Germany
推荐引用方式 GB/T 7714	Luo, Yang-Ping,Nemeth, Peter,Liu, Chao,et al. HOT SUBDWARF STARS OBSERVED IN LAMOST DR1-ATMOSPHERIC PARAMETERS FROM SINGLE-LINED SPECTRA[J]. ASTROPHYSICAL JOURNAL,2016,818(2).
APA	Luo, Yang-Ping,Nemeth, Peter,Liu, Chao,Deng, Li-Cai,&Han, Zhan-Wen.(2016).HOT SUBDWARF STARS OBSERVED IN LAMOST DR1-ATMOSPHERIC PARAMETERS FROM SINGLE-LINED SPECTRA.ASTROPHYSICAL JOURNAL,818(2).
MLA	Luo, Yang-Ping,et al."HOT SUBDWARF STARS OBSERVED IN LAMOST DR1-ATMOSPHERIC PARAMETERS FROM SINGLE-LINED SPECTRA".ASTROPHYSICAL JOURNAL 818.2(2016).