KINEMATICS OF THE X-SHAPED MILKY WAY BULGE: EXPECTATIONS FROM A SELF-CONSISTENT N-BODY MODEL

	KINEMATICS OF THE X-SHAPED MILKY WAY BULGE: EXPECTATIONS FROM A SELF-CONSISTENT N-BODY MODEL
	Qin, Yujing 1,2; Shen, Juntai 1; Li, Zhao-Yu 1; Mao, Shude3,4,5,6 ; Smith, Martin C.1; Rich, R. Michael 7; Kunder, Andrea 8; Liu, Chao3
刊名	ASTROPHYSICAL JOURNAL
	2015-07-20
卷号	808 期号:1
关键词	Galaxy: bulge Galaxy: kinematics and dynamics Galaxy: structure
英文摘要	We explore the kinematics (both the radial velocity and the proper motion) of the vertical X-shaped feature in the Milky Way with an N-body bar/bulge model. From the solar perspective, the distance distribution of particles is double-peaked in fields passing through the X-shape. The separation and amplitude ratio between the two peaks qualitatively match the observed trends toward the Galactic bulge. We confirm clear signatures of cylindrical rotation in the pattern of mean radial velocity across the bar/bulge region. We also find possible imprints of coherent orbital motion inside the bar structure in the radial velocity distribution along l = 0 degrees, where the near and far sides of the bar/bulge show excesses of approaching and receding particles. The coherent orbital motion is also reflected in the slight displacement of the zero-velocity. line in the mean radial velocity. and the displacement of the maximum/minimum in the mean longitudinal proper motion across the bulge region. We find some degree of anisotropy in the stellar velocity within the X-shape, but the underlying orbital family of the X-shape cannot be clearly distinguished. Two potential applications of the X-shape in previous literature are tested, i.e., bulge rotation and Galactic center (GC) measurements. We find that the proper-motion difference between the two sides of the X-shape can be used to estimate the mean azimuthal streaming motion of the bulge, but not the pattern speed of the bar. We also demonstrate that the GC can be located with the X-shape, but the accuracy depends on the fitting scheme, the number of fields, and their latitudinal coverage.
收录类别	SCI
语种	英语
WOS记录号	WOS:000359062500075
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/5639]
专题	国家天文台_光学天文研究部
作者单位	1.Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 4.Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China 5.Tsinghua Univ, Tsinghua Ctr Astrophys, Beijing 100084, Peoples R China 6.Univ Manchester, Jodrell Bank Ctr Astrophys, Manchester M13 9PL, Lancs, England 7.Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA 8.Leibniz Inst Astrophys Potsdam AIP, D-14482 Potsdam, Germany
推荐引用方式 GB/T 7714	Qin, Yujing,Shen, Juntai,Li, Zhao-Yu,et al. KINEMATICS OF THE X-SHAPED MILKY WAY BULGE: EXPECTATIONS FROM A SELF-CONSISTENT N-BODY MODEL[J]. ASTROPHYSICAL JOURNAL,2015,808(1).
APA	Qin, Yujing.,Shen, Juntai.,Li, Zhao-Yu.,Mao, Shude.,Smith, Martin C..,...&Liu, Chao.(2015).KINEMATICS OF THE X-SHAPED MILKY WAY BULGE: EXPECTATIONS FROM A SELF-CONSISTENT N-BODY MODEL.ASTROPHYSICAL JOURNAL,808(1).
MLA	Qin, Yujing,et al."KINEMATICS OF THE X-SHAPED MILKY WAY BULGE: EXPECTATIONS FROM A SELF-CONSISTENT N-BODY MODEL".ASTROPHYSICAL JOURNAL 808.1(2015).