Evidence for Significant Growth in the Stellar Mass of Brightest Cluster Galaxies over the Past 10 Billion Years
Evidence for Significant Growth in the Stellar Mass of Brightest Cluster Galaxies over the Past 10 Billion Years
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DOI：
10.1111/j.1365-2966.2012.21984.x
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发表时间：
2012-08
影响因子：
4.8
通讯作者：
C. Lidman;J. Suherli;A. Muzzin;G. Wilson;R. Demarco;S. Brough;A. Rettura;J. Cox;A. DeGroot-A.-DeGroo
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文献类型：
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作者：
C. Lidman;J. Suherli;A. Muzzin;G. Wilson;R. Demarco;S. Brough;A. Rettura;J. Cox;A. DeGroot-A.-DeGroo
使用新的和已发表的数据，我们构建了一个样本的160个最亮的星系团（BCGs）跨越红移区间0.03 < z < 1.63。我们使用这个样本，其中涵盖了70%的宇宙历史，测量的增长后，校正的BCG的恒星质量和它的生活在集群的质量之间的相关性的恒星质量的BCGs。我们发现BCGs的恒星质量在z = 0.9和z = 0.2之间增加了1.8 ± 0.3倍。与以前的工作相比，我们的结果更接近半解析模型的预测。然而，相对于z = 0.2的BCGs，z = 0.9的BCGs仍然比这些模型的预测大1.5倍。BCGs在z = 1处的星星形成率通常太低，以至于不能产生大量的质量。相反，很可能大部分的质量积聚主要是通过干合并发生的，其中可能有一半的质量损失到集群的集群内介质中。
Using new and published data, we construct a sample of 160 brightest cluster galaxies (BCGs) spanning the redshift interval 0.03 < z < 1.63. We use this sample, which covers 70 per cent of the history of the universe, to measure the growth in the stellar mass of BCGs after correcting for the correlation between the stellar mass of the BCG and the mass of the cluster in which it lives. We find that the stellar mass of BCGs increases by a factor of 1.8 ± 0.3 between z = 0.9 and z = 0.2. Compared to earlier works, our result is closer to the predictions of semi-analytic models. However, BCGs at z = 0.9, relative to BCGs at z = 0.2, are still a factor of 1.5 more massive than the predictions of these models. Star formation rates in BCGs at z ∼ 1 are generally too low to result in significant amounts of mass. Instead, it is likely that most of the mass build up occurs through mainly dry mergers in which perhaps half of the mass is lost to the intra-cluster medium of the cluster.