Angular momentum evolution of bulge stars in disc galaxies in NIHAO

doi:10.1093/mnras/sty3010

	Angular momentum evolution of bulge stars in disc galaxies in NIHAO
	Wang, Liang 1; Obreschkow, Danail 1; Lagos, Claudia del P.1,2; Sweet, Sarah M.3; Fisher, Deanne 3; Glazebrook, Karl 3; Maccio, Andrea V.4,5; Dutton, Aaron A.4; Kang, Xi6
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2019-02-01
卷号	482 期号:4 页码:5477-5491
关键词	methods: numerical galaxies: bulges galaxies: evolution galaxies: formation galaxies: kinematics and dynamics galaxies: spiral
ISSN号	0035-8711
DOI	10.1093/mnras/sty3010
通讯作者	Wang, Liang(liang.wang@uwa.edu.au)
英文摘要	We study the origin of bulge stars and their angular momentum (AM) evolution in 10 spiral galaxies with baryonic masses above 10(10) M-circle dot in the Numerical Investigation of a Hundred Astrophysical Objects galaxy formation simulations. The simulated galaxies are in good agreement with observations of the relation between the specific AM and mass of the baryonic component and the stellar bulge-to-total ratio (B/T). We divide the star particles at z = 0 into disc and bulge components using a hybrid photometric/kinematic decomposition method that identifies all the central mass above an exponential disc profile as the 'bulge'. By tracking the bulge star particles back in time, we find that on average 95 per cent of the bulge stars formed in situ, 3 per cent formed ex situ in satellites of the same halo, and only 2 per cent formed ex situ in external galaxies. The evolution of the AM distribution of the bulge stars paints an interesting picture: The higher the final B/T, the more the specific AM remains preserved during the bulge formation. In all cases, bulge stars migrate significantly towards the central region, reducing their average galactocentric radius by roughly a factor 2, independently of the final B/T value. However, in the higher B/T (greater than or similar to 0.2) objects, the velocity of the bulge stars increases and the AM of the bulge is almost conserved, whereas at lower B/T values, the velocity of the bulge stars decreases and the AM of the bulge reduces. The correlation between the evolution of the AM and B/T suggests that bulge formation and disc formation are closely linked and cannot be treated as independent processes.
WOS关键词	COSMOLOGICAL SIMULATIONS ; FEEDBACK ; MATTER ; DARK ; PROJECT ; DYNAMICS ; ORIGIN ; HALO ; GAS ; PSEUDOBULGES
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	OXFORD UNIV PRESS
WOS记录号	WOS:000462327300091
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/24210]
专题	中国科学院紫金山天文台
通讯作者	Wang, Liang
作者单位	1.Univ Western Australia, Int Ctr Radio Astron Res ICRAR, M468,35 Stirling Hwy, Crawley, WA 6009, Australia 2.Swinburne Univ Technol, ARC Ctr Excellence All Sky Astrophys 3 Dimens AST, POB 218, Hawthorn, Vic 3122, Australia 3.Swinburne Univ Technol, Ctr Astrophys & Supercomp, POB 218, Hawthorn, Vic 3122, Australia 4.New York Univ Abu Dhabi, POB 129188, Abu Dhabi, U Arab Emirates 5.Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany 6.Partner Grp MPI Astron, Purple Mt Observ, 2 West Beijing Rd, Nanjing 210008, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Wang, Liang,Obreschkow, Danail,Lagos, Claudia del P.,et al. Angular momentum evolution of bulge stars in disc galaxies in NIHAO[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2019,482(4):5477-5491.
APA	Wang, Liang.,Obreschkow, Danail.,Lagos, Claudia del P..,Sweet, Sarah M..,Fisher, Deanne.,...&Kang, Xi.(2019).Angular momentum evolution of bulge stars in disc galaxies in NIHAO.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,482(4),5477-5491.
MLA	Wang, Liang,et al."Angular momentum evolution of bulge stars in disc galaxies in NIHAO".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 482.4(2019):5477-5491.