Spitzer Observations of the Brightest Galaxies in X-Ray-Luminous Clusters
Spitzer Observations of the Brightest Galaxies in X-Ray-Luminous Clusters
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斯皮策对 X 射线发光星团中最亮星系的观测
DOI：
10.1086/504519
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Cfa
中科院分区：
文献类型：
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作者：
E. Egami;K. Misselt;G. Rieke;M. Wise;G. Neugebauer;J. Kneib;E. Floc’h;G. Smith;M. Blaylock;H. Dole;D. Frayer;J.;O. Krause;C. Papovich;P. Pérez;J. S. Observatory;U. Arizona;Mit;Center for Space Research;Oamp;Laboratoire d'Astrophysique de Marseille;Caltech;O. Paris;U. Birmingham;Ias;Universite de Paris Sud;SSCCaltech;Cfa
我们研究了位于X射线发光星系团核心0.15<；z<；0.35的最亮星系团(BCG)的红外性质。与其他质量较大的早期类型星系相比，大多数BCGs的红外亮度并不是特别高，这表明星系团环境对BCGs的红外亮度影响很小。然而，例外的是样本中三个X射线最亮的星系团A1835、Z3146和A2390中的BCG。它们的光谱能量分布(SED)具有明显的远红外峰，其中两个(A1835和Z3146)可归类为发光红外星系(LIRGS：LIR>；1011 L☉)。尽管射电活动星系核(活动星系核)被发现在BCG中很普遍，但从红外SED信号判断，这三个BCG的红外光度很可能是由恒星形成提供动力的。考虑到辐射气体冷却时间越短的星团拥有更多红外线发光的星团的总体趋势，这种增强的恒星形成可能是由于冷却的星团气体积聚在星云上造成的。
We have studied the infrared properties of the brightest cluster galaxies (BCGs) located in the cores of X-ray-luminous clusters at 0.15 < z < 0.35. The majority of the BCGs are not particularly infrared-luminous compared with other massive early-type galaxies, suggesting that the cluster environment has little influence on the infrared luminosities of the BCGs. The exceptions, however, are the BCGs in the three X-ray-brightest clusters in the sample, A1835, Z3146, and A2390. These BCGs have a prominent far-infrared peak in their spectral energy distributions (SEDs), and two of them (those in A1835 and Z3146) can be classified as luminous infrared galaxies (LIRGs: LIR > 1011 L☉). Although radio AGNs (active galactic nuclei) are found to be prevalent among the BCGs, the infrared luminosities of these three BCGs, judged from the infrared SED signatures, are likely to be powered by star formation. Considering the overall trend that clusters with shorter radiative gas cooling times harbor more infrared-luminous BCGs, the enhanced star formation may be caused by the cooling cluster gas accreting onto the BCGs.