Masses and Ages for 230,000 LAMOST Giants, via Their Carbon and Nitrogen Abundances

	Masses and Ages for 230,000 LAMOST Giants, via Their Carbon and Nitrogen Abundances
	Ho, Anna Y. Q.1,2; Rix, Hans-Walter 2; Ness, Melissa K.2; Hogg, David W.2,3,4,5; Liu, Chao6 ; Ting, Yuan-Sen 7,8
刊名	ASTROPHYSICAL JOURNAL
	2017-05-20
卷号	841 期号:1
关键词	methods: data analysis methods: statistical stars: abundances stars: fundamental parameters surveys techniques: spectroscopic
英文摘要	We measure carbon and nitrogen abundances to a precision of less than or similar to 0.1 dex for 450,000 giant stars from their low-resolution (R similar to 1800) LAMOST DR2 survey spectra. We use these [C/M] and[N/M] measurements, together with empirical relations based on the APOKASC sample, to infer stellar masses and implied ages for 230,000 of these objects to 0.08 dex and 0.2 dex respectively. We use The. Cannon, a data-driven approach to spectral modeling, to construct a predictive model for LAMOST spectra. Our reference set comprises 8125 stars observed in common between the APOGEE and LAMOST surveys, taking seven APOGEE DR12 labels (parameters) as ground truth: T-eff, log g,[M/H],[alpha/M], [C/M],[N/M], and A(k). We add seven colors to the Cannon model, based on the g, r, i, J, H, K, W1, W2 magnitudes from APASS, 2MASS, and WISE, which improves our constraints on T-eff and log g by up to 20% and on A(k) by up to 70%. Cross-validation of the model demonstrates that, for high-S/N objects, our inferred labels agree with the APOGEE values to within 50 K in temperature, 0.04 mag in A(k), and <0.1 dex in log g,[M/H], [C/M],[N/M], and[alpha/M]. We apply the model to 450,000 giants in LAMOST DR2 that have not been observed by APOGEE. This demonstrates that precise individual abundances can be measured from low-resolution spectra. and represents the largest catalog to date of homogeneous stellar [C/M],[N/M], masses, and ages. As a result, we greatly increase the number and sky coverage of stars with mass and age estimates.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	DIGITAL SKY SURVEY ; RED GIANTS ; MILKY-WAY ; ATMOSPHERIC PARAMETERS ; STELLAR POPULATIONS ; GALACTIC DISK ; DATA RELEASE ; SDSS-III ; ALL-SKY ; KEPLER
收录类别	SCI
语种	英语
WOS记录号	WOS:000402310500026
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/8814]
专题	国家天文台_光学天文研究部
作者单位	1.CALTECH, Cahill Ctr Astrophys, MC 249-17,1200 E Calif Blvd, Pasadena, CA 91125 USA 2.Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany 3.Simons Ctr Data Anal, 160 Fifth Ave,7th Floor, New York, NY 10010 USA 4.NYU, Dept Phys, Ctr Cosmol & Particle Phys, 4 Washington Pl,Room 424, New York, NY 10003 USA 5.NYU, Ctr Data Sci, 726 Broadway,7th Floor, New York, NY 10003 USA 6.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Datun Rd 20A, Beijing 100012, Peoples R China 7.Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA 8.Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Cotter Rd, Weston, ACT 2611, Australia
推荐引用方式 GB/T 7714	Ho, Anna Y. Q.,Rix, Hans-Walter,Ness, Melissa K.,et al. Masses and Ages for 230,000 LAMOST Giants, via Their Carbon and Nitrogen Abundances[J]. ASTROPHYSICAL JOURNAL,2017,841(1).
APA	Ho, Anna Y. Q.,Rix, Hans-Walter,Ness, Melissa K.,Hogg, David W.,Liu, Chao,&Ting, Yuan-Sen.(2017).Masses and Ages for 230,000 LAMOST Giants, via Their Carbon and Nitrogen Abundances.ASTROPHYSICAL JOURNAL,841(1).
MLA	Ho, Anna Y. Q.,et al."Masses and Ages for 230,000 LAMOST Giants, via Their Carbon and Nitrogen Abundances".ASTROPHYSICAL JOURNAL 841.1(2017).