Modelling the evolution of galaxy clustering
Modelling the evolution of galaxy clustering
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模拟星系团的演化
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
C. Lacey
中科院分区：
文献类型：
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作者：
C. Baugh;Andrew J Benson;S. Cole;C. Frenk;C. Lacey
现在，在红移到z ~ 3的范围内测量星系团已经成为可能。我们使用一个星系形成的半解析模型来计算星系相关函数随红移的演化。我们说明了如何聚类进化的程度是敏感的样本选择的细节。对于一个固定的视星等极限，在较高的红移选择星系位于越来越稀少的暗物质晕，与一般人口的星系在每个红移的地方。因此，这些星系是潜在的暗物质分布的高度偏差的示踪剂，并表现出比暗物质更强的聚集性。一般来说，以共动单位测量的相关长度，首先随着红移的增加而减小，然后在更高的红移处再次增加。我们发现，经常用来解释的角度相关函数的暗淡星系的e-模型给出了一个不充分的描述集群的演变，并提供任何物理洞察集群过程。我们比较我们的预测与一个简单的，流行的模型，其中假设星系和暗晕之间的一一对应。定性地说，这个模型在高红移下再现了正确的演化行为，但定量结果可能会有很大的误差。我们的理论预期与Carlberg等人和Postman等人的高红移聚类数据吻合得很好，但高于Le Fevre等人的测量结果。
Measurements of galaxy clustering are now becoming possible over a range of redshifts out to z∼ 3. We use a semi-analytic model of galaxy formation to compute the expected evolution of the galaxy correlation function with redshift. We illustrate how the degree of clustering evolution is sensitive to the details of sample selection. For a fixed apparent magnitude limit, galaxies selected at higher redshifts are located in progressively rarer dark matter haloes, compared with the general population of galaxies in place at each redshift. As a result these galaxies are highly biased tracers of the underlying dark matter distribution and exhibit stronger clustering than the dark matter. In general, the correlation length measured in comoving units, decreases at first with increasing redshift, before increasing again at higher redshift. We show that the e-model often used to interpret the angular correlation function of faint galaxies gives an inadequate description of the evolution of clustering, and offers no physical insight into the clustering process. We compare our predictions with those of a simple, popular model in which a one-to-one correspondence between galaxies and dark haloes is assumed. Qualitatively, this model reproduces the correct evolutionary behaviour at high redshift, but the quantitative results can be significantly in error. Our theoretical expectations are in good agreement with the high redshift clustering data of Carlberg et al. and Postman et al. but are higher than the measurements of Le Fevre et al.