期刊
ASTRONOMY & ASTROPHYSICS
卷 562, 期 -, 页码 -出版社
EDP SCIENCES S A
DOI: 10.1051/0004-6361/201322531
关键词
Galaxy: general; Galaxy: fundamental parameters; Galaxy: kinematics and dynamics; Galaxy: structure; Galaxy: halo
资金
- German Research Foundation [DFG-STE-710/4-3, SPP 1177, SFB 88]
- Australian Astronomical Observatory
- Leibniz-Institut fur Astrophysik Potsdam (ALP)
- Australian National University
- Australian Research Council
- French National Research Agency
- European Research Council [ERC-StG 240271 Galactica]
- Istituto Nazionale di Astrofisica at Padova
- Johns Hopkins University
- National Science Foundation of the USA [AST-0908326]
- W. M. Keck foundation
- Macquarie University
- Netherlands Research School for Astronomy
- Natural Sciences and Engineering Research Council of Canada
- Slovenian Research Agency
- Swiss National Science Foundation
- Science & Technology Facilities Council of the UK,
- Opticon
- Strasbourg Observatory
- University of Groningen
- University of Heidelberg
- University of Sydney
- STFC [ST/G002509/1, ST/K000977/1, PP/D001242/1, ST/J00149X/1, ST/K00106X/1, ST/G002479/1, ST/K000985/1, PP/D001528/1] Funding Source: UKRI
- Science and Technology Facilities Council [ST/G002509/1, ST/K000977/1, PP/D001528/1, ST/K000985/1, ST/G002479/1, PP/D001242/1, ST/H00243X/1, ST/K00106X/1, ST/J00149X/1] Funding Source: researchfish
- UK Space Agency [PP/D006570/1, ST/K00056X/1, ST/I000852/1] Funding Source: researchfish
We made new estimates of the Galactic escape speed at various Galactocentric radii using the latest data release of the RAdial Velocity Experiment (RAVE DR4). Compared to previous studies we have a database that is larger by a factor of 10, as well as reliable distance estimates for almost all stars. Our analysis is based on statistical analysis of a rigorously selected sample of 90 highvelocity halo stars from RAVE and a previously published data set. We calibrated and extensively tested our method using a suite of cosmological simulations of the formation of Milky Way-sized galaxies. Our best estimate of the local Galactic escape speed, which we define as the minimum speed required to reach three virial radii R-340, is 533(-41)(+54), km s(-1) (90% confidence), with an additional 4% systematic uncertainty, where R-340 is the Galactocentric radius encompassing a mean overdensity of 340 times the critical density for closure in the Universe. From the escape speed we further derived estimates of the mass of the Galaxy using a simple mass model with two options for the mass profile of the dark matter halo: an unaltered and an adiabatically contracted Navarro, Frenk & White (NEW) sphere. If we fix the local circular velocity, the latter profile yields a significantly- higher mass than the uncontracted halo, but if we instead use the statistics for halo concentration parameters in large cosmological simulations as a constraint, we find very similar masses for both models. Our best estimate for M-340, the mass interior to R-340 (dark matter and baryons), is 1.31(-0.3)(+0.4) x 10(12) M-circle dot (corresponds to M-200 = 1.6(-0.4)(+0.5) x 10(12) M-circle dot). This estimate is in good agreement with recently published, independent mass estimates based on the kinematics of more distant halo stars and the satellite galaxy Leo I.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据