Kinematics of Milky Way satellites in a Lambda cold dark matter universe
Kinematics of Milky Way satellites in a Lambda cold dark matter universe
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DOI：
10.1111/j.1365-2966.2010.17287.x
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发表时间：
2010-03
影响因子：
4.8
通讯作者：
L. Strigari;C. Frenk;S. White
中科院分区：
文献类型：
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作者：
L. Strigari;C. Frenk;S. White
我们调查了兰姆达冷暗物质(Λ)星系晕的亚晕是否具有与银河系卫星的观测特性一致的潜力，特别是那些拥有高质量光度和运动学数据的卫星：Fornax、Leo I、Sculptor、Sextans和Carina。我们将具有各向同性速度色散张量的球面模型与观测到的圆形平均恒星数、视线速度色散分布和视线速度分布进行了比较。我们在宝瓶座计划的六个高分辨率暗物质光晕中识别出次光晕，对于这些光晕，球面平均位势与五个星系中的每个星系都非常吻合。特别是，我们的简单的一积分模型再现了内部区域的观测结果，证明这些数据与Λ清洁发展机制的预期完全一致，不需要核心暗物质分布。对于五颗卫星中的四颗，拟合需要中等尖端的恒星密度分布。然而，LEO I的恒星计数数据确实需要恒星计数的核心分布。目前的数据表明，这五颗卫星可能由Λ清洁发展机制亚晕托管，其最大圆周速度在10-30公里范围内，S−1。
We investigate whether the subhaloes of Lambda cold dark matter (ΛCDM) galaxy haloes have potentials consistent with the observed properties of Milky Way satellites, particularly those with high-quality photometric and kinematic data: Fornax, Leo I, Sculptor, Sextans and Carina. We compare spherical models with isotropic velocity dispersion tensors to the observed, circularly averaged star counts, line-of-sight velocity dispersion profiles and line-of-sight velocity distributions. We identify subhaloes within the six high-resolution dark matter haloes of the Aquarius Project for which the spherically averaged potentials result in excellent fits to each of the five galaxies. In particular, our simple one-integral models reproduce the observations in the inner regions, proving that these data are fully consistent with ΛCDM expectations and do not require cored dark matter distributions. For four of the five satellites the fits require moderately cusped stellar density profiles. The star count data for Leo I, however, do require a cored distribution of star counts. Current data suggest that these five satellites may be hosted by ΛCDM subhaloes with maximum circular velocities in the range 10–30 km s−1.