Close-binary evolution I. Tidally induced shear mixing in rotating binaries

	Close-binary evolution I. Tidally induced shear mixing in rotating binaries
	Song, HF1,2,4 ; Maeder, A 2; Meynet, G 2; Huang RQ(黄润乾)3 ; Ekstrom, S 2; Granada, A 2
刊名	ASTRONOMY & ASTROPHYSICS
	2013-08
卷号	556
关键词	binaries: close stars: rotation stars: abundances stars: evolution
ISSN号	0004-6361
通讯作者	Song, HF (reprint author), Guizhou Univ, Coll Sci, Guiyang 550025, Guizhou Provinc, Peoples R China.
产权排序	第三完成单位
英文摘要	Context. Tides are known to play an important role in binary evolution, leading in particular to synchronization of axial and orbital rotations and to binary mass transfer. Aims. We study how tides in a binary system induce some specific internal shear mixing that can substantially modify the evolution of close binaries prior to mass transfer. Methods. We constructed numerical models accounting for tidal interactions, meridional circulation, transport of angular momentum, shears and horizontal turbulence. Furthermore, we considered a variety of orbital periods and initial rotation velocities. Results. Depending on orbital periods and rotation velocities, tidal effects may spin down (spin-down case) or spin up (spin-up case) the axial rotation. In both cases, tides may induce a high internal differential rotation. The resulting tidally induced shear mixing is so efficient that the internal distributions of angular velocity and chemical elements are highly influenced. The evolutionary tracks are modified, and in for spin down as well as for spin up, large amounts of nitrogen can be transported to the stellar surfaces before any binary mass transfer. Meridional circulation, when properly treated as a advection, always tends to counteract the tidal interaction, tending to spin up the surface when it is braked down and vice versa. As a consequence, the times needed for the axial angular velocity to become equal to the orbital angular velocity may be longer than given by typical synchronization timescales. Moreover, because of the meridional circulation some differential rotation remains in tidally locked binary systems.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	M-CIRCLE-DOT ; ANGULAR-MOMENTUM LOSS ; RED SUPERGIANT RATIO ; MASSIVE STAR MODELS ; MAIN-SEQUENCE STARS ; O-TYPE STARS ; STELLAR EVOLUTION ; PRESUPERNOVA EVOLUTION ; MERIDIONAL CIRCULATION ; B-STARS
收录类别	SCI ; EI
原文出处	http://www.aanda.org/articles/aa/abs/2013/08/aa21870-13/aa21870-13.html
语种	英语
WOS记录号	WOS:000323893500100
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5232]
专题	云南天文台_恒星物理研究组云南天文台_中国科学院天体结构与演化重点实验室
作者单位	1.College of Science, Guizhou University, Guiyang, 550025 Guizhou Province PR China 2.Geneva Observatory, Geneva University, 1290 Sauverny, Switzerland 3.National Astronomical Observatories/Yunnan Observatory, the Chinese Academy of Sciences, Kunming, 650011 Yunnan Province, PR China 4.Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, 650011 Kunming, PR China
推荐引用方式 GB/T 7714	Song, HF,Maeder, A,Meynet, G,et al. Close-binary evolution I. Tidally induced shear mixing in rotating binaries[J]. ASTRONOMY & ASTROPHYSICS,2013,556.
APA	Song, HF,Maeder, A,Meynet, G,Huang RQ,Ekstrom, S,&Granada, A.(2013).Close-binary evolution I. Tidally induced shear mixing in rotating binaries.ASTRONOMY & ASTROPHYSICS,556.
MLA	Song, HF,et al."Close-binary evolution I. Tidally induced shear mixing in rotating binaries".ASTRONOMY & ASTROPHYSICS 556(2013).