ADIABATIC MASS LOSS IN BINARY STARS. I. COMPUTATIONAL METHOD

	ADIABATIC MASS LOSS IN BINARY STARS. I. COMPUTATIONAL METHOD
	Ge HW(葛宏伟)1,2,3 ; Hjellming, MS 4; Webbink, RF 5; Chen XF(陈雪飞)1,2 ; Han ZW(韩占文)1,2
刊名	ASTROPHYSICAL JOURNAL
	2010-07-10
卷号	717 期号:2 页码:724-738
关键词	binaries: close stars: evolution stars: interiors stars: mass-loss
ISSN号	0004-637X
通讯作者	Ge, HW (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	The asymptotic response of donor stars in interacting binary systems to very rapid mass loss is characterized by adiabatic expansion throughout their interiors. In this limit, energy generation and heat flow through the stellar interior can be neglected. We model this response by constructing model sequences, beginning with a donor star filling its Roche lobe at an arbitrary point in its evolution, holding its specific entropy and composition profiles fixed as mass is removed from the surface. The stellar interior remains in hydrostatic equilibrium. Luminosity profiles in these adiabatic models of mass-losing stars can be reconstructed from the specific entropy profiles and their gradients. These approximations are validated by comparison with time-dependent binary mass transfer calculations. We describe how adiabatic mass-loss sequences can be used to quantify threshold conditions for dynamical timescale mass transfer, and to establish the range of post-common envelope binaries that are allowed energetically. In dynamical timescale mass transfer, the adiabatic response of the donor star drives it to expand beyond its Roche lobe, leading to runaway mass transfer and the formation of a common envelope with its companion star. For donor stars with surface convection zones of any significant depth, this runaway condition is encountered early in mass transfer, if at all; but for main-sequence stars with radiative envelopes, it may be encountered after a prolonged phase of thermal timescale mass transfer, a so-called delayed dynamical instability. We identify the critical binary mass ratio for the onset of dynamical timescale mass transfer as that ratio for which the adiabatic response of the donor star radius to mass loss matches that of its Roche lobe at some point during mass transfer; if the ratio of donor to accretor masses exceeds this critical value, dynamical timescale mass transfer ensues. In common envelope evolution, the dissipation of orbital energy of the binary provides the energy to eject the common envelope; the energy budget for this process consists essentially of the initial orbital energy of the binary and the initial self-energies of the binary components. We emphasize that, because the stellar core and envelope contribute mutually to each other's gravitational potential energy, proper evaluation of the total energy of a star requires integration over the entire stellar interior, and not just over the ejected envelope alone as commonly assumed. We show that the change in total energy of the donor star, as a function of its remaining mass along an adiabatic mass-loss sequence, can be calculated either by integration over initial and final models, or by a path integral along the mass-loss sequence. That change in total energy of the donor star, combined with the requirement that both remnant donor and its companion star fit within their respective Roche lobes, then circumscribes energetically possible survivors of common envelope evolution.
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]	COMMON ENVELOPE EVOLUTION ; THERMONUCLEAR REACTION-RATES ; DOUBLE WHITE-DWARFS ; SUBDWARF-B-STARS ; OR-EQUAL-TO ; STELLAR EVOLUTION ; POPULATION SYNTHESIS ; DYNAMICAL INSTABILITIES ; SYSTEMS ; SUPERNOVAE
收录类别	SCI
原文出处	http://iopscience.iop.org/0004-637X/717/2/724/
语种	英语
WOS记录号	WOS:000280650800011
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/4496]
专题	云南天文台_大样本恒星演化研究组云南天文台_中国科学院天体结构与演化重点实验室
作者单位	1.National Astronomical Observatories/Yunnan Observatory, The Chinese Academy of Sciences, Kunming 650011, China 2.Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011, China 3.Graduate University of Chinese Academy of Sciences, Beijing 100039, China 4.Cherryville, NC 28021, USA 5.Department of Astronomy, University of Illinois, 1002 W. Green St., Urbana, IL 61801, USA
推荐引用方式 GB/T 7714	Ge HW,Hjellming, MS,Webbink, RF,et al. ADIABATIC MASS LOSS IN BINARY STARS. I. COMPUTATIONAL METHOD[J]. ASTROPHYSICAL JOURNAL,2010,717(2):724-738.
APA	Ge HW,Hjellming, MS,Webbink, RF,Chen XF,&Han ZW.(2010).ADIABATIC MASS LOSS IN BINARY STARS. I. COMPUTATIONAL METHOD.ASTROPHYSICAL JOURNAL,717(2),724-738.
MLA	Ge HW,et al."ADIABATIC MASS LOSS IN BINARY STARS. I. COMPUTATIONAL METHOD".ASTROPHYSICAL JOURNAL 717.2(2010):724-738.