A robust sample of submillimetre galaxies: constraints on the prevalence of dusty, high-redshift starbursts
A robust sample of submillimetre galaxies: constraints on the prevalence of dusty, high-redshift starbursts
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亚毫米星系的可靠样本：对尘埃、高红移星暴普遍存在的限制
DOI：
10.1111/j.1365-2966.2005.09639.x
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发表时间：
2004
影响因子：
4.8
通讯作者：
Stephen Chapman
中科院分区：
文献类型：
--
作者：
R. Ivison;R. Ivison;I. Smail;J. Dunlop;T. Greve;A. Swinbank;J. Stevens;J. Stevens;A. Mortier;S. Serjeant;T. Targett;F. Bertoldi;A. Blain;Stephen Chapman
在目前的（亚）毫米[（亚）毫米]测量中检测到的大多数源的适度意义可能会影响一些分析，因为在通常选择的≥3.0-3.5σ的目录中包含虚假源。在这里，我们开发和应用双测量提取技术，以亚毫米波普通用户测辐射热仪阵列（SCUBA）和马克斯-普朗克毫米波测辐射热仪（MAMBO）的洛克曼孔图像。在5σ以上，我们的亚毫米星系（SMG）目录比之前的样本更加稳健，通过与噪音叠加进入的真实的但微弱的SMG（低于和接近混淆极限）的可能性降低。我们的选择技术产生19 SMG的有效面积为165弧分2，其中我们预计最多有两个是由于机会叠加的SCUBA和MAMBO噪声峰。测量的有效通量极限（在1.1 mm处为1.4 mJy）与我们的深1.4 GHz图像（a = 4.6 μJy束-1）非常匹配。前者对极端红移的发光尘埃星系敏感，而后者则探测z ≤ 3区域。我们的强大SMG中有很大一部分（约80%）具有无线电对应物，考虑到10%的杂散源污染，这表明非常遥远的SMG（z >> 3）不太可能占明亮SMG总数的10%以上。这意味着几乎所有的S 1 mm ≥ 4 mJy SMG人群都适合通过最深电流放射成像进行研究。我们使用这些无线电同行提供一个经验校准SMG目录中的位置不确定性。然后，我们继续概述通过submm中的样本选择获取无线电识别SMG的红移。到无线电和光学/红外线中的对应物选择，到光谱仪掩模上的狭缝放置。我们确定的中位数z = 2.05 ± 0.41，从一个样本的六个安全的红移明确的无线电识别的亚毫米源和z = 2.14 ± 0.27时，我们包括亚毫米源与多个无线电同行和/或不太可靠的红移。这些数字与以前的估计是一致的，这表明我们对明亮SMG人口的中值红移的了解并没有受到所采用的源目录的低显著性的影响。
The modest significance of most sources detected in current (sub)millimetre [(sub)mm] surveys can potentially compromise some analyses due to the inclusion of spurious sources in catalogues typically selected at ≥3.0-3.5σ. Here, we develop and apply a dual-survey extraction technique to Submillimetre Common-User Bolometer Array (SCUBA) and Max-Planck Millimetre Bolometer (MAMBO) images of the Lockman Hole. Cut above 5σ, our catalogue of submillimetre galaxies (SMGs) is more robust than previous samples, with a reduced likelihood of real, but faint SMGs (beneath and around the confusion limit) entering via superposition with noise. Our selection technique yields 19 SMGs in an effective area of 165 arcmin 2 , of which we expect at most two to be due to chance superposition of SCUBA and MAMBO noise peaks. The effective flux limit of the survey (∼4 mJy at ∼ 1 mm) is well matched to our deep 1.4-GHz image (a = 4.6 μJy beam -1 ). The former is sensitive to luminous, dusty galaxies at extreme redshifts whilst the latter probes the z ≤ 3 regime. A high fraction of our robust SMGs (∼80 per cent) have radio counterparts which, given the ∼10 per cent contamination by spurious sources, suggests that very distant SMGs (z >> 3) are unlikely to make up more than ∼10 per cent of the bright SMG population. This implies that almost all of the S 1 mm ≥ 4 mJy SMG population is amenable to study via the deepest current radio imaging. We use these radio counterparts to provide an empirical calibration of the positional uncertainty in SMG catalogues. We then go on to outline the acquisition of redshifts for radio-identified SMGs, from sample selection in the submm. to counterpart selection in the radio and optical/infrared, to slit placement on spectrograph masks. We determine a median of z = 2.05 ± 0.41 from a sample of six secure redshifts for unambiguous radio-identified submm sources and z = 2.14 ± 0.27 when we include submm sources with multiple radio counterparts and/or less reliable redshifts. These figures are consistent with previous estimates, suggesting that our knowledge of the median redshift of bright SMG population has not been biased by the low significance of the source catalogues employed.