Cosmic clocks: a tight radius-velocity relationship for HI-selected galaxies

doi:10.1093/mnras/sty275

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	Cosmic clocks: a tight radius-velocity relationship for HI-selected galaxies
	Meurer, Gerhardt R.1; Obreschkow, Danail 1; Wong, O. Ivy 1,2; Zheng, Zheng 3; Audcent-Rossi, Fiona M.1; Hanish, D. J.4
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2018-05-01
卷号	476 期号:2 页码:1624-1636
关键词	galaxies: dwarf galaxies: fundamental parameters galaxies: kinematics and dynamics galaxies: spiral galaxies: structure
ISSN号	0035-8711
DOI	10.1093/mnras/sty275
英文摘要	HI-selected galaxies obey a linear relationship between their maximum detected radius R-max and rotational velocity. This result covers measurements in the optical, ultraviolet, and HI emission in galaxies spanning a factor of 30 in size and velocity, from small dwarf irregulars to the largest spirals. Hence, galaxies behave as clocks, rotating once a Gyr at the very outskirts of their discs. Observations of a large optically selected sample are consistent, implying this relationship is generic to disc galaxies in the low redshift Universe. A linear radius-velocity relationship is expected from simple models of galaxy formation and evolution. The total mass within R-max has collapsed by a factor of 37 compared to the present mean density of the Universe. Adopting standard assumptions, we find a mean halo spin parameter. in the range 0.020-0.035. The dispersion in lambda, 0.16 dex, is smaller than expected from simulations. This may be due to the biases in our selection of disc galaxies rather than all haloes. The estimated mass densities of stars and atomic gas at R-max are similar (similar to 0.5M(circle dot)pc(-2)), indicating outer discs are highly evolved. The gas consumption and stellar population build time-scales are hundreds of Gyr, hence star formation is not driving the current evolution of outer discs. The estimated ratio between R-max and disc scalelength is consistent with long-standing predictions from monolithic collapse models. Hence, it remains unclear whether disc extent results from continual accretion, a rapid initial collapse, secular evolution, or a combination thereof.
资助项目	National Natural Science Foundation of China[11703036] ; National Aeronautics and Space Administration (NASA)[NAG5-13083] ; National Aeronautics and Space Administration (NASA)[GALEX GI04-0105-0009] ; National Aeronautics and Space Administration (NASA)[NNX09AF85G] ; National Aeronautics and Space Administration
WOS关键词	INITIAL MASS FUNCTION ; DARK-MATTER HALOES ; STAR-FORMATION EFFICIENCY ; TULLY-FISHER RELATIONS ; ON SPIRAL GALAXIES ; SURFACE BRIGHTNESS ; DWARF GALAXIES ; GALACTIC DISKS ; IRREGULAR GALAXIES ; NEUTRAL HYDROGEN
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	OXFORD UNIV PRESS
WOS记录号	WOS:000430940900012
资助机构	National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration (NASA) ; National Aeronautics and Space Administration ; National Aeronautics and Space Administration
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/21218]
专题	中国科学院国家天文台
通讯作者	Meurer, Gerhardt R.; Wong, O. Ivy
作者单位	1.Univ Western Australia, Int Ctr Radio Astron Res, 35 Stirling Highway, Crawley, WA 6009, Australia 2.Univ Sydney, Sch Phys, ARC Ctr Excellence All Sky Astrophys CAASTRO, Bldg A28, Sydney, NSW 2006, Australia 3.Chinese Acad Sci, Natl Astron Observ, A20 Datun Rd, Beijing 100012, Peoples R China 4.CALTECH, Spitzer Sci Ctr, MC 220-6,1200 E Calif Blvd, Pasadena, CA 91125 USA
推荐引用方式 GB/T 7714	Meurer, Gerhardt R.,Obreschkow, Danail,Wong, O. Ivy,et al. Cosmic clocks: a tight radius-velocity relationship for HI-selected galaxies[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2018,476(2):1624-1636.
APA	Meurer, Gerhardt R.,Obreschkow, Danail,Wong, O. Ivy,Zheng, Zheng,Audcent-Rossi, Fiona M.,&Hanish, D. J..(2018).Cosmic clocks: a tight radius-velocity relationship for HI-selected galaxies.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,476(2),1624-1636.
MLA	Meurer, Gerhardt R.,et al."Cosmic clocks: a tight radius-velocity relationship for HI-selected galaxies".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 476.2(2018):1624-1636.