The Dusty Young Universe - Star formation in high-redshift Quasars

在相当一部分最高红移类星体（z bbb50）中探测到（亚）毫米波长的热尘埃发射，这意味着在大爆炸后的第一个十亿年中，大量的尘埃一定已经合成了。斯皮策在24 μm的观测也表明，在大多数高红移类星体中，非常热的尘埃存在于QSO核心附近。然而，即使将这些观测结果结合起来，也只能分别捕捉到λrest bbb100 μm和λrest <5 μm的尘埃发射尾部。为了测量λ ~10 ~ 100 μm的尘埃发射峰，需要采用灵敏的远红外（FIR）观测。这对于高红移qso中的尘埃特性和早期AGN宿主星系中活跃恒星形成的发生率的简明图像至关重要，这可能对我们理解星系演化以及黑洞质量与星系凸起之间相互作用的起源产生巨大影响。我们的赫歇尔关键计划目前收集了71个类星体在z bbbb50的红外光谱光度测量。我们在此要求资助一个博士后研究职位，以领导项目数据的分析，出版和分发。拟议的拨款将使我们能够全面分析一套完整的光谱能量分布（SEDs），涵盖紫外线到红外线的其余框架。SEDs的多组分拟合和建模将为早期宇宙中具有统计意义的类星体样本提供热光度、尘埃质量和恒星形成率。

The detections of thermal dust emission at (sub-)mm wavelengths in a significant fraction of the highest redshift quasars (z >5) imply that large amounts of dust must have been synthesized already during the first billion years after the Big Bang. Observations at 24 μm with Spitzer have also shown that very hot dust is present close to the QSO core in most high redshift quasars. However, even combined these observations only catch the tails of the dust emission at λrest >100 μm and λrest <5 μm, respectively. In order to measure the peak of the dust emission at λrest ~10−100 μm, sensitive far-infrared (FIR) observations are needed. This is paramount for a concise picture of the dust properties in high redshift QSOs and the incidence of vigorous star-formation in early AGN host galaxies, which may have immense impact on our understanding of galaxy evolution and the origin of the interplay between black hole masses and galaxy bulges. Our Herschel Key Program currently collects such FIR photometry for 71 quasars at z >5. We here ask for funding for one post-doctoral research position to lead the analysis, publication, and distribution of the project data. The proposed funding would enable the comprehensive analysis of a complete set of spectral energy distributions (SEDs) covering the rest frame UV through infrared regime. Multi-component fitting and modeling of the SEDs will provide bolometric luminosities, dust masses and star-formation rates for a statistically significant sample of quasars in the early universe.