ARE HIGH VELOCITY PEAKS IN THE MILKY WAY BULGE DUE TO THE BAR?
文献类型：期刊论文
| 作者 | Li, Zhao-Yu1; Shen, Juntai1 ; Rich, R. Michael2; Kunder, Andrea3; Mao, Shude4,5
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| 刊名 | ASTROPHYSICAL JOURNAL LETTERS
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| 出版日期 | 2014-04-10 |
| 卷号 | 785期号:1页码:17-22 |
| 关键词 | Galaxy: bulge Galaxy: kinematics and dynamics Galaxy: structure surveys |
| 英文摘要 | Recently the commissioning APOGEE observations of the Galactic bulge reported that a significant fraction of stars (similar to 10%) are in a cold (sigma nu approximate to 30 km s(-1)) high velocity peak (Galactocentric radial velocity approximate to 200 km s-1). These stars are speculated to reflect the stellar orbits in the Galactic bar. In this study, we use two N-body models of a Milky Way-like disk galaxy with different bar strengths to critically examine this possibility. The general trends of the Galactocentric radial velocity distribution in observations and simulations are similar, but neither our models nor the BRAVA data reveal a statistically significant cold high velocity peak. A Monte Carlo test further suggests that it is possible for a spurious high velocity peak to appear if there are only a limited number of stars observed. Thus, the reported cold high velocity peak, even if it is real, is unlikely due to stars on the bar-supporting orbits. Our models do predict an excess of stars with high radial velocity, but not in a distinct peak. In the distance-velocity diagram, the high velocity particles in different fields exist at a similar distance similar to 8.5 +/- 1 kpc away from the Sun. This result may be explained by geometric intersections between the line-of-sight and the particle orbits; high velocity stars naturally exist approximately at the tangent point, without constituting a distinct peak. We further demonstrate that even without the presence of a bar structure, particle motions in an axisymmetric disk can also exhibit an excess of high velocity stars. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | SPLIT RED CLUMP ; GALACTIC BULGE ; DISK GALAXIES ; STELLAR BARS ; BOXY BULGE ; EVOLUTION ; KINEMATICS ; METALLICITY ; MORPHOLOGY ; STARS |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000334345000017 |
| 源URL | [http://119.78.226.72/handle/331011/16233]  |
| 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, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China 2.Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA 3.Leibniz Inst Astrophys Potsdam AIP, D-14482 Potsdam, Germany 4.Chinese Acad Sci, Natl Astron Observ, Galaxy & Cosmol Div, Beijing 100012, Peoples R China 5.Univ Manchester, Ctr Astrophys, Jodrell Bank, Manchester M13 9PL, Lancs, England |
| 推荐引用方式 GB/T 7714 | Li, Zhao-Yu,Shen, Juntai,Rich, R. Michael,et al. ARE HIGH VELOCITY PEAKS IN THE MILKY WAY BULGE DUE TO THE BAR?[J]. ASTROPHYSICAL JOURNAL LETTERS,2014,785(1):17-22. |
| APA | Li, Zhao-Yu,Shen, Juntai,Rich, R. Michael,Kunder, Andrea,&Mao, Shude.(2014).ARE HIGH VELOCITY PEAKS IN THE MILKY WAY BULGE DUE TO THE BAR?.ASTROPHYSICAL JOURNAL LETTERS,785(1),17-22. |
| MLA | Li, Zhao-Yu,et al."ARE HIGH VELOCITY PEAKS IN THE MILKY WAY BULGE DUE TO THE BAR?".ASTROPHYSICAL JOURNAL LETTERS 785.1(2014):17-22. |
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来源：上海天文台
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