THE STELLAR AND GAS KINEMATICS OF THE LITTLE THINGS DWARF IRREGULAR GALAXY NGC 1569

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 星系中的恒星形成研究团组

	THE STELLAR AND GAS KINEMATICS OF THE LITTLE THINGS DWARF IRREGULAR GALAXY NGC 1569
	Johnson, Megan 1,2,3; Hunter, Deidre A.2; Oh, Se-Heon 4,5; Zhang, Hong-Xin 2,6; Elmegreen, Bruce 7; Brinks, Elias 8; Tollerud, Erik 9; Herrmann, Kimberly 2
刊名	ASTRONOMICAL JOURNAL
	2012-11-01
卷号	144 期号:5 页码:152(22pp)
关键词	galaxies: dwarf galaxies: individual (NGC 1569) galaxies: kinematics and dynamics galaxies: starburst techniques: spectroscopic
ISSN号	0004-6256
英文摘要	In order to understand the formation and evolution of Magellanic-type dwarf irregular (dIm) galaxies, one needs to understand their three-dimensional structure. We present measurements of the stellar velocity dispersion in NGC 1569, a nearby post-starburst dIm galaxy. The stellar vertical velocity dispersion, sigma(z), coupled with the maximum rotational velocity derived from H I observations, V-max, gives a measure of how kinematically hot the galaxy is, and, therefore, indicates its structure. We conclude that the stars in NGC 1569 are in a thick disk with a V-max/sigma(z) = 2.4 +/- 0.7. In addition to the structure, we analyze the ionized gas kinematics from O III observations along the morphological major axis. These data show evidence for outflow from the inner starburst region and a potential expanding shell near supermassive star cluster (SSC) A. When compared to the stellar kinematics, the velocity dispersion of the stars increases in the region of SSC A supporting the hypothesis of an expanding shell. The stellar kinematics closely follow the motion of the gas. Analysis of high-resolution H I data clearly reveals the presence of an H I cloud that appears to be impacting the eastern edge of NGC 1569. Also, an ultra-dense H I cloud can be seen extending to the west of the impacting H I cloud. This dense cloud is likely the remains of a dense H I bridge that extended through what is now the central starburst area. The impacting Hi cloud was the catalyst for the starburst, thus turning the dense gas into stars over a short timescale, similar to 1 Gyr. We performed a careful study of the spectral energy distribution using infrared, optical, and ultraviolet photometry, producing a state-of-the-art mass model for the stellar disk. This mass modeling shows that stars dominate the gravitational potential in the inner 1 kpc. The dynamical mass of NGC 1569, derived from V-max, shows that the disk may be dark matter deficient in the inner region, although, when compared to the expected virial mass determined from halo abundance matching techniques, the dark matter profile seems to agree with the observed mass profile at a radius of 2.2 kpc.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	X-RAY SURVEY ; STAR-FORMATION ; DARK-MATTER ; STARBURST PROPERTIES ; INTERSTELLAR-MEDIUM ; GALACTIC OUTFLOW ; SPIRAL GALAXIES ; ROTATION CURVES ; LARGE-SAMPLE ; IONIZED-GAS
收录类别	SCI
语种	英语
WOS记录号	WOS:000310530400028
公开日期	2013-01-31
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/8078]
专题	紫金山天文台_星系中的恒星形成研究团组
作者单位	1.Natl Radio Astron Observ, Green Bank, WV 24944 USA 2.Lowell Observ, Flagstaff, AZ 86001 USA 3.Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA 4.Univ Western Australia, ICRAR, Crawley, WA 6009, Australia 5.Univ Sydney, ARC Ctr Excellence All Sky Astrophys CAASTRO, Sch Phys, Redfern, NSW 2016, Australia 6.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 7.IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA 8.Univ Hertfordshire, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England 9.Univ Calif Irvine, Ctr Cosmol, Dept Phys & Astron, Irvine, CA 92697 USA
推荐引用方式 GB/T 7714	Johnson, Megan,Hunter, Deidre A.,Oh, Se-Heon,et al. THE STELLAR AND GAS KINEMATICS OF THE LITTLE THINGS DWARF IRREGULAR GALAXY NGC 1569[J]. ASTRONOMICAL JOURNAL,2012,144(5):152(22pp).
APA	Johnson, Megan.,Hunter, Deidre A..,Oh, Se-Heon.,Zhang, Hong-Xin.,Elmegreen, Bruce.,...&Herrmann, Kimberly.(2012).THE STELLAR AND GAS KINEMATICS OF THE LITTLE THINGS DWARF IRREGULAR GALAXY NGC 1569.ASTRONOMICAL JOURNAL,144(5),152(22pp).
MLA	Johnson, Megan,et al."THE STELLAR AND GAS KINEMATICS OF THE LITTLE THINGS DWARF IRREGULAR GALAXY NGC 1569".ASTRONOMICAL JOURNAL 144.5(2012):152(22pp).