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arXiv 1005.3155astro-ph.CO
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z = 0 - 2区域大质量星系远红外射电相关和红外SEDs的演化

Evolution of the Far-Infrared-Radio Correlation and Infrared SEDs of Massive Galaxies over z = 0 - 2

N. Bourne, L. Dunne, R. J. Ivison, S. J. Maddox, M. Dickinson, D. T. Frayer

摘要:

我们调查的远红外无线电相关(FRC)的恒星质量选择星系在扩展的钱德拉深场南使用远红外成像斯皮策和射电成像从甚大阵和巨型米波射电望远镜。我们在红移箱中堆叠,以探测噪音和混乱极限以下的星系。无线电通量K-校正使用观测到的流量比,导致光谱指数的演变的初步证据。我们比较了本地星系的光谱能量分布(SED)模板的K-校正FIR通量,并表明,数据是最好的拟合由一个静止的螺旋模板(M51),而不是一个温暖的星暴(M82)或ULIRG(Arp 220),这意味着在高红移的大质量星系的冷尘埃占主导地位。相比之下,我们测量的总红外光度与高恒星形成率是一致的。我们观察到,FRC指数(q)不演变显着超过z=0-2时,计算K-校正24或160-妈妈测光,但使用70-妈妈通量导致一个明显的下降q超过z~1。这表明在高红移时SED会发生一些变化,要么是在静止坐标系~25- 35 μ m处光谱变陡,要么是在~ 70 μ m处光谱不足,导致总的红外/射电比下降。我们将我们的结果与文献中的其他工作进行比较,并发现与最近的高红移FRC,大质量星系的高特定恒星形成率和这些星系中的冷尘埃温度的研究结果的协同作用。

英文摘要:

We investigate the far-infrared-radio correlation (FRC) of stellar-mass-selected galaxies in the Extended Chandra Deep Field South using far-infrared imaging from Spitzer and radio imaging from the Very Large Array and Giant Metre-Wave Radio Telescope. We stack in redshift bins to probe galaxies below the noise and confusion limits. Radio fluxes are K-corrected using observed flux ratios, leading to tentative evidence for an evolution in spectral index. We compare spectral energy distribution (SED) templates of local galaxies for K-correcting FIR fluxes, and show that the data are best fit by a quiescent spiral template (M51) rather than a warm starburst (M82) or ULIRG (Arp220), implying a predominance of cold dust in massive galaxies at high redshift. In contrast we measure total infrared luminosities that are consistent with high star-formation rates. We observe that the FRC index (q) does not evolve significantly over z=0-2 when computed from K-corrected 24 or 160-mum photometry, but that using 70-mum fluxes leads to an apparent decline in q beyond z~1. This suggests some change in the SED at high redshift, either a steepening of the spectrum at rest-frame ~25-35mum or a deficiency at ~70mum leading to a drop in the total infrared/radio ratios. We compare our results to other work in the literature and find synergies with recent findings on the high-redshift FRC, high specific star-formation rates of massive galaxies and the cold dust temperatures in these galaxies.

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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