arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0712.0965astro-ph
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根据中红外和远红外观测估算z~2以下星系的总红外光度

Estimating the total infrared luminosity of galaxies up to z~2 from mid- and far-infrared observations

N. Bavouzet, H. Dole, E. Le Floc'h, K. I. Caputi, G. Lagache, C. S. Kochanek

摘要:

本文给出了Spitzer观测到的星系静止坐标系8、24、70和160 μ m单色光光度与实测红外总光度L_IR之间的相关关系。我们的样本由372个恒星形成星系组成,分别在8,24,70和160 μ m处进行探测和通量测量。我们有93%的这些来源的光谱红移,和准确的光度红移的其余部分。我们还使用了堆叠分析来测量在较高的红移较暗的源的红外通量。我们发现,单色的中红外和远红外光度与总的红外光度有很强的相关性,我们的叠加分析证实,这些相关性也保持在较高的红移。本文给出了在z~2(z~1.1)范围内,超红外类(LIRGs)单色光光度与红外总光度L_IR之间的关系式。特别地,我们可以用8和24 μ m通量预测L_IR,准确率分别为37%和54%,而最好的示踪剂是70 μ m通量。组合波段可以得到稍微更准确的估计。例如,结合8和24 μ m的光度预测L_IR的准确度为34%。我们的结果与以前的研究基本一致,微小的变化可能是由于样本选择标准的差异。我们可以排除红移到z~1的尘埃性质的强演化。最后,我们表明,红外和亚毫米观测是建立恒星形成星系完整样本的补充手段,前者对z<~2更敏感,后者对z>~2更敏感。

英文摘要:

We present the observed correlations between rest-frame 8, 24, 70 and 160 um monochromatic luminosities and measured total infrared luminosities L_IR of galaxies detected by Spitzer. Our sample consists of 372 star-forming galaxies with individual detections and flux measurements at 8, 24, 70 and 160 um. We have spectroscopic redshifts for 93% of these sources, and accurate photometric redshifts for the remainder. We also used a stacking analysis to measure the IR fluxes of fainter sources at higher redshifts. We show that the monochromatic mid and far-infrared luminosities are strongly correlated with the total infrared luminosity and our stacking analysis confirms that these correlations also hold at higher redshifts. We provide relations between monochromatic luminosities and total infrared luminosities L_IR that should be reliable up to z~2 (z~1.1) for ULIRGs (LIRGs). In particular, we can predict L_IR with accuracies of 37% and 54% from the 8 and 24 um fluxes, while the best tracer is the 70 um flux. Combining bands leads to slightly more accurate estimates. For example, combining the 8 and 24 um luminosities predicts L_IR with an accuracy of 34%. Our results are generally compatible with previous studies, and the small changes are probably due to differences in the sample selection criteria. We can rule out strong evolution in dust properties with redshift up to z~1. Finally, we show that infrared and sub-millimeter observations are complementary means of building complete samples of star-forming galaxies, with the former being more sensitive for z<~2 and the latter at higher z>~2.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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