干旱区生态环境知识资源中心(Arid): Age Determination in Upper Scorpius with Eclipsing Binaries

Arid

DOI	10.3847/1538-4357/aafe09
	Age Determination in Upper Scorpius with Eclipsing Binaries
	David, Trevor J.1,2; Hillenbrand, Lynne A.2; Gillen, Edward 3; Cody, Ann Marie 4; Howell, Steve B.4; Isaacson, Howard T.5; Livingston, John H.6
通讯作者	David, Trevor J.
来源期刊	ASTROPHYSICAL JOURNAL
ISSN	0004-637X
EISSN	1538-4357
出版年	2019
卷号	872 期号:2
英文摘要	The Upper Scorpius OB association is the nearest region of recent massive star formation and thus an important benchmark for investigations concerning stellar evolution and planet formation timescales. We present nine eclipsing binaries (EBs) in Upper Scorpius, three of which are newly reported here and all of which were discovered from K2 photometry. Joint fitting of the eclipse photometry and radial velocities from newly acquired Keck I/HIRES spectra yields precise masses and radii for those systems that are spectroscopically double-lined. The binary orbital periods in our sample range from 0.6 to 100 days, with total masses ranging from 0.2 to 8 M-circle dot. At least 33% of the EBs reside in hierarchical multiples, including two triples and one quadruple. We use these EBs to develop an empirical mass-radius relation for pre-main-sequence stars and evaluate the predictions of widely used stellar evolutionary models. We report evidence for an age of 5-7 Myr, which is self-consistent in the mass range of 0.3-5 M-circle dot and based on the fundamentally determined masses and radii of EBs. Evolutionary models including the effects of magnetic fields imply an age of 9-10 Myr. Our results are consistent with previous studies that indicate that many models systematically underestimate the masses of low-mass stars by 20%-60% based on Hertzsprung-Russell diagram analyses. We also consider the dynamical states of several binaries and compare with expectations from tidal dissipation theories. Finally, we identify RIK 72 b as a long-period transiting brown dwarf (M = 59.2 +/- 6.8 M-Jup, R = 3.10 +/- 0.31 R-Jup, P approximate to 97.8 days) and an ideal benchmark for brown dwarf cooling models at 5-10 Myr.
英文关键词	binaries: eclipsing binaries: spectroscopic Hertzsprung-Russell and C-M diagrams open clusters and associations: individual (Upper Scorpius) stars: evolution stars: pre-main sequence
类型	Article
语种	英语
国家	USA ; England ; Japan
开放获取类型	Green Accepted, Green Submitted, Green Published
收录类别	SCI-E
WOS记录号	WOS:000459323800014
WOS关键词	PRE-MAIN-SEQUENCE ; LOW-MASS STARS ; EXTRASOLAR GIANT PLANETS ; BROWN DWARF DESERT ; EQUATION-OF-STATE ; DIFFERENTIAL ROTATION ; SPECTROSCOPIC BINARY ; STELLAR EVOLUTION ; ACCURATE MASSES ; MAGNETIC-FIELDS
WOS类目	Astronomy & Astrophysics
WOS研究方向	Astronomy & Astrophysics
来源机构	University of California, Berkeley
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/214434
作者单位	1.CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA; 2.CALTECH, Dept Astron, Pasadena, CA 91125 USA; 3.Cavendish Lab, Astrophys Grp, JJ Thomson Ave, Cambridge CB3 0HE, England; 4.NASA, Ames Res Ctr, Moffett Field, CA 94035 USA; 5.Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA; 6.Univ Tokyo, Dept Astron, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan
推荐引用方式 GB/T 7714	David, Trevor J.,Hillenbrand, Lynne A.,Gillen, Edward,et al. Age Determination in Upper Scorpius with Eclipsing Binaries[J]. University of California, Berkeley,2019,872(2).
APA	David, Trevor J..,Hillenbrand, Lynne A..,Gillen, Edward.,Cody, Ann Marie.,Howell, Steve B..,...&Livingston, John H..(2019).Age Determination in Upper Scorpius with Eclipsing Binaries.ASTROPHYSICAL JOURNAL,872(2).
MLA	David, Trevor J.,et al."Age Determination in Upper Scorpius with Eclipsing Binaries".ASTROPHYSICAL JOURNAL 872.2(2019).