A new way to measure the departure from thermodynamic equilibrium in stellar atmospheres

	A new way to measure the departure from thermodynamic equilibrium in stellar atmospheres
	Qu ZQ(屈中权)1 ; Hao LF(郝龙飞)1,2 ; Yan XL(闫晓理)1,2 ; Xu, CL3
刊名	RESEARCH IN ASTRONOMY AND ASTROPHYSICS
	2009-02
卷号	9 期号:2 页码:205-212
关键词	line: formation radiative transfer stars: atmospheres
ISSN号	1674-4527
通讯作者	Qu, ZQ (reprint author), Chinese Acad Sci, Yunnan Astron Observ, Natl Astron Observ, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	A new way to measure the departure from thermodynamic equilibrium is proposed based on the departure factor which evaluates the deviation from a Boltzmann level distribution, used by Short and Hauschildt (2005) and others. The way is based on an explicit relationship describing the departure factor as a function of line to continuum source, dynamic temperature and line photon frequency, under three assumptions that the scattering can be neglected, the background continuum can be treated. as a Planck function, and finally the complete redistribution can be true. It has the advantage,that the departure can be very conveniently evaluated from the spectral analysis with only the radiative transfer involved. Some physical insights are recovered for some extreme cases. Some example calculations of the departure are presented for the quiet Sun, faint solar flare and strong solar flare for the, generally used solar chromospheric lines: H alpha, H beta, Call H, K and triplet. It is revealed that in the case of solar flares, the departure is less than thermodynamic equilibrium along the larger depth range than in the quiet sun due to chromospheric condensation. It becomes hard to distinguish the departures for the different lines of the same atom or ion. It is expected that this investigation can be constructive for studying stellar atmospheres in cases where the three assumptions are close to reality.
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]	CHROMOSPHERIC CONDENSATION ; MAGNETIC-FIELDS ; LINE ; FLARE ; MODEL
收录类别	SCI
原文出处	http://iopscience.iop.org/1674-4527/9/2/009/
语种	英语
WOS记录号	WOS:000264845000009
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/6150]
专题	云南天文台_太阳物理研究组
作者单位	1.Yunnan Astronomical Observatory/National Astronomical Observatories, Chinese Academy of Sciences, Kunming 650011, China 2.Graduate School, Chinese Academy of Sciences, Beijing 100049, China 3.Mathematics Department, Yunnan Normal University, Kunming 650122, China
推荐引用方式 GB/T 7714	Qu ZQ,Hao LF,Yan XL,et al. A new way to measure the departure from thermodynamic equilibrium in stellar atmospheres[J]. RESEARCH IN ASTRONOMY AND ASTROPHYSICS,2009,9(2):205-212.
APA	Qu ZQ,Hao LF,Yan XL,&Xu, CL.(2009).A new way to measure the departure from thermodynamic equilibrium in stellar atmospheres.RESEARCH IN ASTRONOMY AND ASTROPHYSICS,9(2),205-212.
MLA	Qu ZQ,et al."A new way to measure the departure from thermodynamic equilibrium in stellar atmospheres".RESEARCH IN ASTRONOMY AND ASTROPHYSICS 9.2(2009):205-212.