Structure and luminosity of neutrino-cooled accretion disks

CORC > 厦门大学 > 物理技术－已发表论文

	Structure and luminosity of neutrino-cooled accretion disks
	Liu, T. ; Gu, W. M. ; Xue, L. ; Lu, J. F. ; Gu WM(顾为民)
刊名	http://dx.doi.org/10.1086/513689
	2007-06-01
关键词	GAMMA-RAY BURSTS DOMINATED ACCRETION PHYSICAL MODELS BLACK-HOLES STARS BREMSSTRAHLUNG EVOLUTION EMISSION OPACITY STEP
英文摘要	Neutrino-cooled hyperaccretion disks around stellar-mass black holes are plausible candidates for the central engines of gamma-ray bursts. We calculate the one-dimensional structure and the annihilation luminosity of such disks. The neutrino optical depth is of crucial importance in determining the neutrino cooling rate and is in turn dependent on the electron fraction, the free nucleon fraction, and the electron degeneracy, for a given density and temperature of the disk matter. We construct a bridging formula for the electron fraction that works for various neutrino optical depths and give exact definitions for the free proton fraction and free neutron fraction. We show that the electron degeneracy has important effects, in the sense that it increases the absorption optical depth for neutrinos and, along with the neutronization processes favored by high temperature, causes the electron fraction to drop below 0.1 in the inner region of the disk. The resulting neutrino annihilation luminosity is considerably reduced in comparison with that obtained in previous works in which the electron degeneracy was not considered and the electron fraction was simply taken to be 0.5, but it is still likely to be adequate for gamma-ray bursts, and it is ejected mainly from the inner region of the disk with an anisotropic distribution.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/70510]
专题	物理技术－已发表论文
推荐引用方式 GB/T 7714	Liu, T.,Gu, W. M.,Xue, L.,et al. Structure and luminosity of neutrino-cooled accretion disks[J]. http://dx.doi.org/10.1086/513689,2007.
APA	Liu, T.,Gu, W. M.,Xue, L.,Lu, J. F.,&顾为民.(2007).Structure and luminosity of neutrino-cooled accretion disks.http://dx.doi.org/10.1086/513689.
MLA	Liu, T.,et al."Structure and luminosity of neutrino-cooled accretion disks".http://dx.doi.org/10.1086/513689 (2007).