AN EXTENDED VIEW OF THE PISCES OVERDENSITY FROM THE SCUSS SURVEY

	AN EXTENDED VIEW OF THE PISCES OVERDENSITY FROM THE SCUSS SURVEY
	Nie, J. D.1; Smith, M. C.2; Belokurov, V.3; Fan, X. H.4; Fan, Z.1; Irwin, M. J.3; Jiang, Z. J.1; Jing, Y. P.5; Koposov, S. E.3; Lesser, M.4
刊名	ASTROPHYSICAL JOURNAL
	2015-09-10
卷号	810 期号:2 页码:1
关键词	Galaxy: halo Galaxy: structure surveys
英文摘要	The South Galactic Cap u-band Sky Survey (SCUSS) is a u-band photometric survey covering about 4000 square degrees of the South Galactic Cap, reaching depths of up to 23 mag. By extending around 1.5 mag deeper than the Sloan Digital Sky Survey (SDSS) single-epoch u data, SCUSS is able to probe a much larger volume of the outer halo, i.e., with SCUSS data blue horizontal branch (BHB) stars can trace the outer halo of the Milky Way as far as 100-150 kpc. Utilizing this advantage we combine the SCUSS u-band with the SDSS DR9 gri photometric bands to identify BHB stars and explore halo substructures. We confirm the existence of the Pisces overdensity, which is a structure in the outer halo (at around 80 kpc) that was discovered using RR Lyrae stars. For the first time we are able to determine its spatial extent, finding that it appears to be part of a stream with a clear distance gradient. The stream, which is similar to 5 degrees wide and stretches along similar to 25 degrees, consists of 20-30 BHBs with a total significance of around 6 sigma over the background. Assuming we have detected the entire stream and that the progenitor has fully disrupted, then the number of BHBs suggests that the original system was similar to a smaller classical or a larger ultra-faint dwarf galaxy. On the other hand, if the progenitor still exists, it can be hunted for by reconstructing its orbit from the distance gradient of the stream. This new picture of the Pisces overdensity sheds new light on the origin of this intriguing system.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	BLUE HORIZONTAL-BRANCH ; DIGITAL SKY SURVEY ; DWARF SPHEROIDAL GALAXY ; HERCULES-AQUILA CLOUD ; WAY STELLAR HALO ; MILKY-WAY ; GALACTIC HALO ; RR LYRAE ; STARS ; SATELLITES
收录类别	SCI
语种	英语
WOS记录号	WOS:000362083700069
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/28372]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 2.Shanghai Astron Observ, Shanghai 200030, Peoples R China 3.Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England 4.Univ Arizona, Steward Observ, Tucson, AZ 85721 USA 5.Shanghai Jiao Tong Univ, Dept Phys & Astron, Ctr Astron & Astrophys, Shanghai 200240, Peoples R China
推荐引用方式 GB/T 7714	Nie, J. D.,Smith, M. C.,Belokurov, V.,et al. AN EXTENDED VIEW OF THE PISCES OVERDENSITY FROM THE SCUSS SURVEY[J]. ASTROPHYSICAL JOURNAL,2015,810(2):1.
APA	Nie, J. D..,Smith, M. C..,Belokurov, V..,Fan, X. H..,Fan, Z..,...&Zou, H..(2015).AN EXTENDED VIEW OF THE PISCES OVERDENSITY FROM THE SCUSS SURVEY.ASTROPHYSICAL JOURNAL,810(2),1.
MLA	Nie, J. D.,et al."AN EXTENDED VIEW OF THE PISCES OVERDENSITY FROM THE SCUSS SURVEY".ASTROPHYSICAL JOURNAL 810.2(2015):1.