A COMMON SURFACE-DENSITY SCALE FOR THE MILKY WAY AND ANDROMEDA DWARF SATELLITES AS A CONSTRAINT ON DARK MATTER MODELS
A COMMON SURFACE-DENSITY SCALE FOR THE MILKY WAY AND ANDROMEDA DWARF SATELLITES AS A CONSTRAINT ON DARK MATTER MODELS
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DOI：
10.1088/2041-8205/803/1/l11
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发表时间：
2015-03
期刊：
影响因子：
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通讯作者：
Kohei Hayashi;M. Chiba
中科院分区：
文献类型：
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作者：
Kohei Hayashi;M. Chiba
为了对暗物质模型施加明确的约束，我们定义和估计了最大圆速度半径内的暗晕的平均表面密度，该最大圆速度对于具有任何暗物质密度分布的各种星系都是可导的。我们发现，无论每个星系中的密度分布如何，在∼10-400Km S−1的最大圆速度范围内，表面密度通常是恒定的。研究发现，冷暗物质模型和暖暗物质模型(分别为CDM和WDM)都可以在高晕质量尺度下自然复制这种共同的表面密度，即使不使用任何合适的程序。然而，我们从银河系和仙女座矮星卫星得到的矮星系尺度的共同表面密度只在大范围的WDM粒子质量中重现，而CDM提供了与观测到的一致性合理的一致性。这是由于在低晕质量尺度下CDM和WDM晕的质量浓度关系存在显著差异。为了解释WDM模型中矮星系尺度的普遍表面密度，我们建议WDM粒子的质量需要大于3keV。
In an attempt to place an explicit constraint on dark matter models, we define and estimate the mean surface density of a dark halo within the radius of the maximum circular velocity, which is derivable for various galaxies with any dark matter density profiles. We find that this surface density is generally constant across a wide range of maximum circular velocities of ∼10–400 km s−1, irrespective of the different density distributions in each of the galaxies. This common surface density at high halo-mass scales is found to be naturally reproduced by both cold and warm dark matter (CDM and WDM, respectively) models, even without employing any fitting procedures. However, the common surface density at dwarf-galaxy scales, which we have derived from the Milky Way and Andromeda dwarf satellites, is reproduced only in a massive range of WDM particle masses, whereas CDM provides reasonable agreement with the observed constancy. This is due to the striking difference between mass–concentration relations for CDM and WDM halos at low halo-mass scales. In order to explain the universal surface density of dwarf-galaxy scales in WDM models, we suggest that WDM particles need to be heavier than 3 keV.