NIHAO X: reconciling the local galaxy velocity function with cold dark matter via mock H i observations

doi:10.1093/mnrasl/slw147

	NIHAO X: reconciling the local galaxy velocity function with cold dark matter via mock H i observations
	Maccio, Andrea V.1,2; Udrescu, Silviu M.1; Dutton, Aaron A.1; Obreja, Aura 1; Wang, Liang 3; Stinson, Greg R.2; Kang, Xi3
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2016-11-21
卷号	463 期号:1 页码:L69-L73
关键词	methods: numerical galaxies: formation galaxies: kinematics and dynamics galaxies: structure cosmology: theory dark matter
ISSN号	0035-8711
DOI	10.1093/mnrasl/slw147
通讯作者	Maccio, Andrea V.(maccio@nyu.edu)
英文摘要	We used 87 high-resolution hydrodynamical cosmological simulations from the NIHAO suite to investigate the relation between the maximum circular velocity (V-max(DM)) of a dark matter halo in a collisionless simulation and the velocity width of the H i gas in the same halo in the hydrodynamical simulation. These two quantities are normally used to compare theoretical and observational velocity functions and have led to a possible discrepancy between observations and predictions based on the cold dark matter (CDM) model. We show that below 100 km s(-1), there is clear bias between H i -based velocities and V-max(DM), that leads to an underestimation of the actual circular velocity of the halo. When this bias is taken into account, the CDM model has no trouble in reproducing the observed velocity function and no lack of low-velocity galaxies is actually present. Our simulations also reproduce the linewidth-stellar mass (Tully-Fisher) relation and H i sizes, indicating that the H i gas in our simulations is as extended as observed. The physical reason for the lower than expected linewidths is that, in contrast to high-mass galaxies, low-mass galaxies no longer have extended thin H i rotating discs, as is commonly assumed.
WOS关键词	MILKY-WAY SATELLITES ; LAMBDA-CDM ; COSMOLOGICAL SIMULATIONS ; GALACTIC SATELLITES ; DWARF GALAXIES ; FIELD GALAXIES ; COSMIC TIME ; ABUNDANCE ; FEEDBACK ; MODEL
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	OXFORD UNIV PRESS
WOS记录号	WOS:000386157100015
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/23414]
专题	中国科学院紫金山天文台
通讯作者	Maccio, Andrea V.
作者单位	1.New York Univ Abu Dhabi, POB 129188, Abu Dhabi, U Arab Emirates 2.Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany 3.Purple Mt Observ, Partner Grp MPI Astron, 2 West Beijing Rd, Nanjing 210008, Peoples R China
推荐引用方式 GB/T 7714	Maccio, Andrea V.,Udrescu, Silviu M.,Dutton, Aaron A.,et al. NIHAO X: reconciling the local galaxy velocity function with cold dark matter via mock H i observations[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2016,463(1):L69-L73.
APA	Maccio, Andrea V..,Udrescu, Silviu M..,Dutton, Aaron A..,Obreja, Aura.,Wang, Liang.,...&Kang, Xi.(2016).NIHAO X: reconciling the local galaxy velocity function with cold dark matter via mock H i observations.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,463(1),L69-L73.
MLA	Maccio, Andrea V.,et al."NIHAO X: reconciling the local galaxy velocity function with cold dark matter via mock H i observations".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 463.1(2016):L69-L73.