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The Milky Way's circular velocity curve to 60 kpc and an estimate of the dark matter halo mass from the kinematics of similar to 2400 SDSS blue horizontal-branch stars
文献类型：期刊论文
| 作者 | Xue, X. X.1,2,3; Rix, H. W.2; Zhao, G.1 ; Fiorentin, P. Re2,4; Naab, T.5; Steinmetz, M.6; van den Bosch, F. C.2; Beers, T. C.7,8; Lee, Y. S.7,8; Bell, E. F.2
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| 刊名 | ASTROPHYSICAL JOURNAL
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| 出版日期 | 2008-09-10 |
| 卷号 | 684期号:2页码:1143-1158 |
| 关键词 | dark matter galaxies : individual (MilkyWay) Galaxy : halo stars : horizontal-branch stars : kinematics |
| 英文摘要 | We derive new constraints on the mass of the Milky Way's dark matter halo, based on 2401 rigorously selected blue horizontal-branch halo stars from SDSS DR6. This sample enables construction of the full line-of-sight velocity distribution at different galactocentric radii. To interpret these distributions, we compare them to matched mock observations drawn from two different cosmological galaxy formation simulations designed to resemble the Milky Way. This procedure results in an estimate of the Milky Way's circular velocity curve to similar to 60 kpc, which is found to be slightly falling from the adopted value of 220 km s(-1) at the Sun's location, and impliesM(< 60 kpc) (4.0 +/- 0.7); 10(11) M-circle dot. The radial dependence of V-cir(r), derived in statistically independent bins, is found to be consistent with the expectations from an NFW dark matter halo with the established stellar mass components at its center. If we assume that an NFW halo profile of characteristic concentration holds, we can use the observations to estimate the virial mass of the Milky Way's dark matter halo, M-vir = 1.0(-0.2)(+0.3) x 10(12) M-circle dot, which is lower than many previous estimates. We have checked that the particulars of the cosmological simulations are unlikely to introduce systematics larger than the statistical uncertainties. This estimate implies that nearly 40% of the baryons within the virial radius of the Milky Way's dark matter halo reside in the stellar components of our Galaxy. A value for M-vir of only similar to 1 x 10(12) M-circle dot also (re) opens the question of whether all of the Milky Way's satellite galaxies are on bound orbits. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000258889000027 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/7435]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | 1.CAS, Natl Astron Observ, Beijing 100012, Peoples R China 2.Max Planck Inst Astron, D-69117 Heidelberg, Germany 3.Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China 4.Univ Ljubljana, Dept Phys, Ljubljana 1000, Slovenia 5.Univ Sternwarte, D-81679 Munich, Germany 6.Astrophys Inst Potsdam, D-14482 Potsdam, Germany 7.Michigan State Univ, CSCE, Dept Phys & Astron, E Lansing, MI 48824 USA 8.Michigan State Univ, JINA, E Lansing, MI 48824 USA 9.Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95060 USA 10.Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA |
| 推荐引用方式 GB/T 7714 | Xue, X. X.,Rix, H. W.,Zhao, G.,et al. The Milky Way's circular velocity curve to 60 kpc and an estimate of the dark matter halo mass from the kinematics of similar to 2400 SDSS blue horizontal-branch stars[J]. ASTROPHYSICAL JOURNAL,2008,684(2):1143-1158. |
| APA | Xue, X. X..,Rix, H. W..,Zhao, G..,Fiorentin, P. Re.,Naab, T..,...&Schneider, D. P..(2008).The Milky Way's circular velocity curve to 60 kpc and an estimate of the dark matter halo mass from the kinematics of similar to 2400 SDSS blue horizontal-branch stars.ASTROPHYSICAL JOURNAL,684(2),1143-1158. |
| MLA | Xue, X. X.,et al."The Milky Way's circular velocity curve to 60 kpc and an estimate of the dark matter halo mass from the kinematics of similar to 2400 SDSS blue horizontal-branch stars".ASTROPHYSICAL JOURNAL 684.2(2008):1143-1158. |
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来源：国家天文台
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