The segregation of baryons and dark matter during halo assembly

doi:10.1093/mnras/stx1391

	The segregation of baryons and dark matter during halo assembly
	Liao, Shihong 2; Frenk, Carlos S.1; Guo, Qi2 ; Wang, Jie2 ; Gao, Liang1,2
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2017-09-01
卷号	470 期号:2 页码:2262-2269
关键词	Methods: Numerical Galaxies: Haloes Galaxies: Structure
DOI	10.1093/mnras/stx1391
文献子类	Article
英文摘要	The standard galaxy formation theory assumes that baryons and dark matter are initially well mixed before becoming segregated due to radiative cooling. We use non-radiative hydrodynamical simulations to explicitly examine this assumption and find that baryons and dark matter can also be segregated due to different characteristics of gas and dark matter during the buildup of the halo. As a result, baryons in many haloes do not originate from the same Lagrangian region as the dark matter. When using the fraction of corresponding dark matter and gas particles in the initial conditions ( the 'paired fraction') as a proxy of the dark matter and gas segregation strength of a halo, on average about 25 per cent of the baryonic and dark matter of the final halo are segregated in the initial conditions. This is at odds with the assumption of the standard galaxy formation model. A consequence of this effect is that the baryons and dark matter of the same halo initially experience different tidal torques and thus their angular momentum vectors are often misaligned. The degree of the misalignment is largely preserved during later halo assembly and can be understood with the tidal torque theory. The result challenges the precision of some semi-analytical approaches that utilize dark matter halo merger trees to infer properties of gas associated with dark matter haloes.
WOS关键词	ANGULAR-MOMENTUM DISTRIBUTION ; GALAXY FORMATION ; GALACTIC HALOS ; DISK GALAXIES ; GAS ; SIMULATION ; ORIGIN ; PROTOGALAXIES ; COSMOLOGY ; UNIVERSE
WOS研究方向	Astronomy & Astrophysics
语种	英语
WOS记录号	WOS:000406839900073
资助机构	NSFC grant(11133003 ; NSFC grant(11133003 ; Newton Advanced Fellowship ; Newton Advanced Fellowship ; ERC Advanced Grant COSMIWAY ; ERC Advanced Grant COSMIWAY ; 'Recruitment Program of Global Youth Experts' of China ; 'Recruitment Program of Global Youth Experts' of China ; NAOC grant(Y434011V01) ; NAOC grant(Y434011V01) ; 973 programme grant(2015CB857005) ; 973 programme grant(2015CB857005) ; 11425312 ; 11425312 ; 11573033 ; 11573033 ; 11622325 ; 11622325 ; 11373029 ; 11373029 ; 11390372) ; 11390372) ; NSFC grant(11133003 ; NSFC grant(11133003 ; Newton Advanced Fellowship ; Newton Advanced Fellowship ; ERC Advanced Grant COSMIWAY ; ERC Advanced Grant COSMIWAY ; 'Recruitment Program of Global Youth Experts' of China ; 'Recruitment Program of Global Youth Experts' of China ; NAOC grant(Y434011V01) ; NAOC grant(Y434011V01) ; 973 programme grant(2015CB857005) ; 973 programme grant(2015CB857005) ; 11425312 ; 11425312 ; 11573033 ; 11573033 ; 11622325 ; 11622325 ; 11373029 ; 11373029 ; 11390372) ; 11390372)
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/20058]
专题	国家天文台_星系宇宙学研究部
作者单位	1.Univ Durham, Sci Labs, Dept Phys, Inst Computat Cosmol, South Rd, Durham DH1 3LE, England 2.Chinese Acad Sci, Key Lab Computat Astrophys, Natl Astron Observ, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Liao, Shihong,Frenk, Carlos S.,Guo, Qi,et al. The segregation of baryons and dark matter during halo assembly[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2017,470(2):2262-2269.
APA	Liao, Shihong,Frenk, Carlos S.,Guo, Qi,Wang, Jie,&Gao, Liang.(2017).The segregation of baryons and dark matter during halo assembly.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,470(2),2262-2269.
MLA	Liao, Shihong,et al."The segregation of baryons and dark matter during halo assembly".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 470.2(2017):2262-2269.