Galaxy Groups Within 3500 km s−1
Galaxy Groups Within 3500 km s−1
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DOI：
10.3847/1538-4357/aa76db
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发表时间：
2017-05
期刊：
影响因子：
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通讯作者：
E. Kourkchi;R. Tully
中科院分区：
文献类型：
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作者：
E. Kourkchi;R. Tully
对我们邻近星系群特性的研究提供了一个独特的机会来观测约束晕质量函数，这是星系形成的基本特征。对各个群的详细研究提供了维里半径、速度色散和质量的代理之间的标度关系系数，这有效地允许在 M⊙ 范围内定义群。在第二个层级，关联被定义为在与宇宙膨胀解耦时延伸到零速度表面的塌陷晕周围的区域。这项研究最显着的结果来自于样本晕质量函数的构建。在 ∼1012 M⊙ 处，预期 Sheth-Tormen 函数出现了一个缓慢变化，使得所有较低质量箱中的光晕计数下降了 ∼3 倍。
A study of the group properties of galaxies in our immediate neighborhood provides a singular opportunity to observationally constrain the halo mass function, a fundamental characterization of galaxy formation. Detailed studies of individual groups have provided the coefficients of scaling relations between a proxy for the virial radius, velocity dispersion, and mass that usefully allow groups to be defined over the range M⊙. At a second hierarchical level, associations are defined as regions around collapsed halos extending to the zero-velocity surface at the decoupling from cosmic expansion. The most remarkable result of the study emerges from the construction of the halo mass function from the sample. At ∼1012 M⊙, there is a jog from the expectation Sheth-Tormen function, such that halo counts drop by a factor ∼3 in all lower mass bins.