The growth of brightest cluster galaxies and intracluster light over the past 10 billion years
The growth of brightest cluster galaxies and intracluster light over the past 10 billion years
复制标题
DOI：
10.1093/mnras/stz3236
复制
发表时间：
2019-11
影响因子：
4.8
通讯作者：
T. DeMaio;Anthony H. Gonzalez;A. Zabludoff;D. Zaritsky;G. Aldering;M. Brodwin;T. Connor;M. Donahue;B. Hayden;J. Mulchaey;Saul Perlmutter;Saul Perlmutter;S. Stanford
中科院分区：
文献类型：
--
作者：
T. DeMaio;Anthony H. Gonzalez;A. Zabludoff;D. Zaritsky;G. Aldering;M. Brodwin;T. Connor;M. Donahue;B. Hayden;J. Mulchaey;Saul Perlmutter;Saul Perlmutter;S. Stanford
我们使用42个星系群和星系团的系综来限制最亮的星系团加上团内光（BCG + ICL）的演化，这些星系群和星系团的红移范围为z = 0.05−1.75，质量为M500，c= 2 × 1013−1015 M。具体地说，我们测量了BCG + ICL恒星质量M_（500，c）与投影半径10 < r < 100 kpc的三个不同时期的关系。在中等红移（$\bar{z}=0.40$）处，我们有最好的数据，我们发现M = M500，c0.48 ± 0.06。固定所有红移的幂律指数，我们将此关系的归一化限制为在$\bar{z}=0.40$比在高红移（$\bar {z}=1.55$）高2.08 ± 0.21倍。我们发现，从中等到低红移（$\bar{z}=0.10$）的关系没有变化。换句话说，对于固定的M500，c，在10 < r < 100 kpc时，M ε从$\bar{z}=1.55$增加到$\bar{z}=0.40$，此后不再显著增加。理论模型预测，在r500，c范围内，团簇从z = 1.5到z = 0的物理质量增长为1.4×，不包括由于r500，c的定义而引起的演化。我们发现，在同一时期内，中心100 kpc内的M增加了3.8倍。因此，在这个中心区域的M介子的增长比整个星系团的物理质量增长大2倍以上。此外，BCG + ICL恒星质量的浓度（定义为10 kpc以内的恒星质量与100 kpc以内的总恒星质量之比）在所有z处都随着M500，c的增加而减小。我们解释这一结果的BCG + ICL在过去的10 Gyr，与恒星质量组装发生在更大的半径在以后的时间内，由内而外的增长的证据。
We constrain the evolution of the brightest cluster galaxy plus intracluster light (BCG + ICL) using an ensemble of 42 galaxy groups and clusters that span redshifts of z = 0.05−1.75 and masses of M500,c= 2 × 1013−1015 M⊙. Specifically, we measure the relationship between the BCG + ICL stellar mass M⋆ and M500,c at projected radii 10 < r < 100 kpc for three different epochs. At intermediate redshift ($\bar{z}=0.40$), where we have the best data, we find M⋆ ∝ M500,c0.48 ± 0.06. Fixing the exponent of this power law for all redshifts, we constrain the normalization of this relation to be 2.08 ± 0.21 times higher at $\bar{z}=0.40$ than at high redshift ($\bar{z}=1.55$). We find no change in the relation from intermediate to low redshift ($\bar{z}=0.10$). In other words, for fixed M500,c, M⋆ at 10 < r < 100 kpc increases from $\bar{z}=1.55$ to $\bar{z}=0.40$ and not significantly thereafter. Theoretical models predict that the physical mass growth of the cluster from z = 1.5 to z = 0 within r500,c is 1.4×, excluding evolution due to definition of r500,c. We find that M⋆ within the central 100 kpc increases by ∼3.8× over the same period. Thus, the growth of M⋆ in this central region is more than a factor of 2 greater than the physical mass growth of the cluster as a whole. Furthermore, the concentration of the BCG + ICL stellar mass, defined by the ratio of stellar mass within 10 kpc to the total stellar mass within 100 kpc, decreases with increasing M500,c at all z. We interpret this result as evidence for inside–out growth of the BCG + ICL over the past 10 Gyr, with stellar mass assembly occurring at larger radii at later times.