Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars

doi:10.3847/1538-4357/aa9bf1

	Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars
	Zhang, Tianmeng5 ; Zhou, Zhimin5 ; Peng, Xiyan5 ; Willman, Beth 2,3; Sand, David J.2; Hargis, Jonathan 4; Crnojevic, Denija 7; Bechtol, Keith 3; Carlin, Jeffrey L.3; Strader, Jay 1
刊名	ASTROPHYSICAL JOURNAL
	2018
卷号	852 期号:1
关键词	Galaxies: Dwarf Galaxies: Individual (Hercules) Local Group Stars: Variables: Rr Lyrae
DOI	10.3847/1538-4357/aa9bf1
文献子类	Article
英文摘要	We investigate the hypothesized tidal disruption of the Hercules ultra-faint dwarf galaxy (UFD). Previous tidal disruption studies of the Hercules UFD have been hindered by the high degree of foreground contamination in the direction of the dwarf. We bypass this issue by using RR Lyrae stars, which are standard candles with a very low field-volume density at the distance of Hercules. We use wide-field imaging from the Dark Energy Camera on CTIO to identify candidate RR Lyrae stars, supplemented with observations taken in coordination with the Beijing-Arizona Sky Survey on the Bok Telescope. Combining color, magnitude, and light-curve information, we identify three new RR Lyrae stars associated with Hercules. All three of these new RR Lyrae stars lie outside its published tidal radius. When considered with the nine RR Lyrae stars already known within the tidal radius, these results suggest that a substantial fraction of Hercules' stellar content has been stripped. With this degree of tidal disruption, Hercules is an interesting case between a visibly disrupted dwarf (such as the Sagittarius dwarf spheroidal galaxy) and one in dynamic equilibrium. The degree of disruption also shows that we must be more careful with the ways we determine object membership when estimating dwarf masses in the future. One of the three discovered RR Lyrae stars sits along the minor axis of Hercules, but over two tidal radii away. This type of debris is consistent with recent models that suggest Hercules' orbit is aligned with its minor axis.
WOS关键词	DARK-MATTER ANNIHILATION ; MILKY-WAY SATELLITE ; SPHEROIDAL GALAXY ; GALACTIC SATELLITES ; VARIABLE-STARS ; COMA BERENICES ; SKY SURVEY ; LOW-MASS ; LEO V ; PHOTOMETRY
WOS研究方向	Astronomy & Astrophysics
语种	英语
WOS记录号	WOS:000419341900006
资助机构	National Astronomical Observatories of China ; National Astronomical Observatories of China ; Chinese Academy of Sciences(XDB09000000 ; Chinese Academy of Sciences(XDB09000000 ; Ministry of Finance ; Ministry of Finance ; Chinese National Natural Science Foundation(11433005) ; Chinese National Natural Science Foundation(11433005) ; NSF Faculty Early Career Development (CAREER)(AST-1151462) ; NSF Faculty Early Career Development (CAREER)(AST-1151462) ; NSF(AST-1412504 ; NSF(AST-1412504 ; Packard Fellowship ; Packard Fellowship ; 114A11KYSB20160057) ; 114A11KYSB20160057) ; AST-1514763) ; AST-1514763) ; National Astronomical Observatories of China ; National Astronomical Observatories of China ; Chinese Academy of Sciences(XDB09000000 ; Chinese Academy of Sciences(XDB09000000 ; Ministry of Finance ; Ministry of Finance ; Chinese National Natural Science Foundation(11433005) ; Chinese National Natural Science Foundation(11433005) ; NSF Faculty Early Career Development (CAREER)(AST-1151462) ; NSF Faculty Early Career Development (CAREER)(AST-1151462) ; NSF(AST-1412504 ; NSF(AST-1412504 ; Packard Fellowship ; Packard Fellowship ; 114A11KYSB20160057) ; 114A11KYSB20160057) ; AST-1514763) ; AST-1514763)
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/20326]
专题	国家天文台_光学天文研究部
作者单位	1.Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA 2.Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA 3.Univ Arizona, LSST, 933 N Cherry Ave, Tucson, AZ 85721 USA 4.Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA 5.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 6.Ohio State Univ, Dept Astron, 140 W 18th Ave, Columbus, OH 43210 USA 7.Texas Tech Univ, Dept Phys & Astron, Box 41051, Lubbock, TX 79409 USA 8.Haverford Coll, Dept Astron, 370 Lancaster Ave, Haverford, PA 19041 USA
推荐引用方式 GB/T 7714	Zhang, Tianmeng,Zhou, Zhimin,Peng, Xiyan,et al. Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars[J]. ASTROPHYSICAL JOURNAL,2018,852(1).
APA	Zhang, Tianmeng.,Zhou, Zhimin.,Peng, Xiyan.,Willman, Beth.,Sand, David J..,...&Garling, Christopher.(2018).Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars.ASTROPHYSICAL JOURNAL,852(1).
MLA	Zhang, Tianmeng,et al."Mapping the Tidal Destruction of the Hercules Dwarf: A Wide-field DECam Imaging Search for RR Lyrae Stars".ASTROPHYSICAL JOURNAL 852.1(2018).