The phase-space density of fermionic dark matter haloes

	The phase-space density of fermionic dark matter haloes
	Shao, Shi1 ; Gao, Liang1,2 ; Theuns, Tom 2,3; Frenk, Carlos S.2
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2013-04-01
卷号	430 期号:3 页码:2346-2357
关键词	methods: numerical galaxies: haloes dark matter
英文摘要	We have performed a series of numerical experiments to investigate how the primordial thermal velocities of fermionic dark matter particles affect the physical and phase-space density profiles of the dark matter haloes into which they collect. The initial particle velocities induce central cores in both profiles, which can be understood in the framework of phase-space density theory. We find that the maximum coarse-grained phase-space density of the simulated haloes (computed in six-dimensional phase space using the ENBID code is very close to the theoretical fine-grained upper bound, while the pseudo-phase-space density, Q similar to rho/sigma(3), overestimates the maximum phase-space density by up to an order of magnitude. The density in the inner regions of the simulated haloes is well described by a 'pseudo-isothermal' profile with a core. We have developed a simple model based on this profile which, given the observed surface brightness profile of a galaxy and its central velocity dispersion, accurately predicts its central phase-space density. Applying this model to the dwarf spheroidal satellites of the Milky Way yields values close to 0.5 keV for the mass of a hypothetical thermal warm dark matter particle, assuming that the satellite haloes have cores produced by warm dark matter free streaming. Such a small value is in conflict with the lower limit of 1.2 keV set by the observations of the Lyman alpha forest. Thus, if the Milky Way dwarf spheroidal satellites have cores, these are likely due to baryonic processes associated with the forming galaxy, perhaps of the kind proposed by Navarro, Eke and Frenk and seen in the recent simulations of galaxy formation in the cold dark matter model.
收录类别	SCI
语种	英语
WOS记录号	WOS:000319260500063
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/5698]
专题	国家天文台_星系宇宙学研究部
作者单位	1.Chinese Acad Sci, Partner Grp, Natl Astron Observ, Max Planck Inst Astrophys, Beijing 100012, Peoples R China 2.Univ Durham, Inst Computat Cosmol, Dept Phys, Sci Labs, Durham DH1 3LE, England 3.Univ Antwerp, Dept Phys, B-2020 Antwerp, Belgium
推荐引用方式 GB/T 7714	Shao, Shi,Gao, Liang,Theuns, Tom,et al. The phase-space density of fermionic dark matter haloes[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2013,430(3):2346-2357.
APA	Shao, Shi,Gao, Liang,Theuns, Tom,&Frenk, Carlos S..(2013).The phase-space density of fermionic dark matter haloes.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,430(3),2346-2357.
MLA	Shao, Shi,et al."The phase-space density of fermionic dark matter haloes".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 430.3(2013):2346-2357.