The source counts of submillimetre galaxies detected at λ= 1.1 mm
The source counts of submillimetre galaxies detected at λ= 1.1 mm
复制标题
DOI：
10.1111/j.1365-2966.2012.20905.x
复制
发表时间：
2012-03
影响因子：
4.8
通讯作者：
K. Scott;G. Wilson;I. Aretxaga;J. Austermann;E. Chapin;J. Dunlop;H. Ezawa;M. Halpern;B. Hatsukade;D. Hughes;R. Kawabe;Sungeun Kim;K. Kohno;J. Lowenthal;A. Montaña;K. Nakanishi;T. Oshima;D. Sanders;D. Scott;N. Scoville;Y. Tamura;D. Welch;Min S Yun;M. Zeballos
中科院分区：
文献类型：
--
作者：
K. Scott;G. Wilson;I. Aretxaga;J. Austermann;E. Chapin;J. Dunlop;H. Ezawa;M. Halpern;B. Hatsukade;D. Hughes;R. Kawabe;Sungeun Kim;K. Kohno;J. Lowenthal;A. Montaña;K. Nakanishi;T. Oshima;D. Sanders;D. Scott;N. Scoville;Y. Tamura;D. Welch;Min S Yun;M. Zeballos
在亚毫米和毫米波长发现的星系的源计数为红外明亮星系的演化提供了重要信息。我们结合了6次在1.1 mm处与Aztec进行的总共1.6°2、均方根深度从0.4到1.7mJy的空白野外调查数据，得出了迄今为止对通量密度为1.1 mm的源数S_1100=1-12mJy的最强约束。使用来自阿兹特克星系团环境调查的额外数据，将计数扩展到S1100∼20mJy，我们看到了相对于S_1100∼13mJy的计数的指数下降和与南极望远镜测量的>；20mJy的亮源计数的平稳连接的初步证据；这种过剩可能是由于强透镜效应造成的。我们将这些计数与几个半解析和唯象模型的预测进行了比较，发现在通量密度≳为4mJy时，大多数模型的一致性很好；然而，我们发现在较低的通量密度下，模型与观测到的1.1 mm计数之间存在显著的差异(≳3σ)，并且没有一个与在S_1100≲2mJy的欧几里得归一化计数的观测结果相一致。因此，我们的新结果可能需要对现有的低光度星系演化模型进行修改。或者，微弱端的测量计数与唯象模型的预测之间的差异可能是由于对局部宇宙中微弱星系的光谱能量分布的有限了解造成的。
The source counts of galaxies discovered at submillimetre and millimetre wavelengths provide important information on the evolution of infrared-bright galaxies. We combine the data from six blank-field surveys carried out at 1.1 mm with AzTEC, totalling 1.6 deg^2 in area with root-mean-square depths ranging from 0.4 to 1.7 mJy, and derive the strongest constraints to date on the 1.1 mm source counts at flux densities S_1100= 1–12 mJy. Using additional data from the AzTEC Cluster Environment Survey to extend the counts to S1100∼ 20 mJy, we see tentative evidence for an enhancement relative to the exponential drop in the counts at S_1100∼ 13 mJy and a smooth connection to the bright source counts at >20 mJy measured by the South Pole Telescope; this excess may be due to strong-lensing effects. We compare these counts to predictions from several semi-analytical and phenomenological models and find that for most the agreement is quite good at flux densities ≳ 4 mJy; however, we find significant discrepancies (≳ 3σ) between the models and the observed 1.1-mm counts at lower flux densities, and none of them is consistent with the observed turnover in the Euclidean-normalized counts at S_1100≲ 2 mJy. Our new results therefore may require modifications to existing evolutionary models for low-luminosity galaxies. Alternatively, the discrepancy between the measured counts at the faint end and predictions from phenomenological models could arise from limited knowledge of the spectral energy distributions of faint galaxies in the local Universe.