Recent observations have demonstrated a significant growth in the integrated stellar mass of the red sequence since z=1, dominated by a steadily increasing number of galaxies with stellar masses M* < 10^11 M_sun. In this paper, we use the COMBO-17 photometric redshift survey in conjunction with deep Spitzer 24 micron data to explore the relationship between star formation and the growth of stellar mass. We calculate `star formation rate functions' in four different redshift slices, splitting also into contributions from the red sequence and blue cloud for the first time. We find that the growth of stellar mass since z=1 is consistent with the integrated star formation rate. Yet, most of the stars formed are in blue cloud galaxies. If the stellar mass already in, and formed in, z<1 blue cloud galaxies were to stay in the blue cloud the total stellar mass in blue galaxies would be dramatically overproduced. We explore the expected evolution of stellar mass functions, finding that in this picture the number of massive M* > 3x10^10 M_sun blue galaxies would also be overproduced; i.e., most of the new stars formed in blue cloud galaxies are in the massive galaxies. We explore a simple truncation scenario in which these `extra' blue galaxies have their star formation suppressed by an unspecified mechanism or mechanisms; simple cessation of star formation in these extra blue galaxies is approximately sufficient to build up the red sequence at M*<10^11 M_sun.
Integrated specific star formation rates of galaxies, groups, and clusters: A continuous upper limit with stellar mass?
目的：我们调查的恒星质量的积累，通过恒星形成的场星系，星系团，和集群，以更好地了解调节恒星形成的物理过程中，不同的晕。研究方法：为了做到这一点，我们通过研究积分比恒星形成率（SSFR），定义为每单位恒星质量的恒星形成率，作为场星系，星系群和星系团样本的积分恒星质量的函数，在0.18 < z < 0.85，将正在进行的恒星形成活动与恒星质量联系起来。恒星形成率（SFR）是从星系和星系团成员的紫外连续谱和星系团星系的发射线通量中推导出来的。恒星质量的计算是从多波段测光，包括近红外波段的星系和集团，并从集群样本的动力学质量。结果：首次提出了星系团和星系群的完整SSFR，并将其与场星系的SSFR联系起来。然而，我们发现一个连续的上限，星系，集团和集群的SSFR恒星质量平面超过7个数量级的恒星质量。这可能表明，在不同质量的暗物质晕中控制恒星形成的物理过程，在从矮星系到大质量星系团的广泛质量范围内具有相同的质量标度。
The Star Formation History and Stellar Assembly of High Redshift Galaxies
我讨论了目前的观测约束的恒星形成和恒星组装历史的星系在高红移。z 2的大质量星系的数据<1 implies that their stellar populations formed at z>，以及它们的形态结构在那之后不久就就位了。斯皮策太空望远镜24微米的观测表明，z ~ 1.5-3的大质量星系中有相当一部分具有高的红外光度，这表明它们正在快速形成恒星，将物质吸积到超大质量黑洞上，或者两者兼而有之。我比较如何观察这些IR活跃阶段的大规模星系的历史约束目前的星系形成模型。
