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

在大部分红移最高的类星体(z&gt；5)中探测到的(亚)毫米波长的热尘埃发射表明，在大爆炸后的头10亿年里，一定已经合成了大量的尘埃。用斯皮策在24μm进行的观测也表明，在大多数高红移类星体中，在类星体核心附近存在非常热的尘埃。然而，即使将这些观测结合在一起，也只能分别捕捉到λRest&gt；100μm和λRest&lt；5μm的尘埃排放的尾部。为了测量λREST~10−100μm的粉尘排放峰值，需要进行灵敏的远红外观测。这对于简明地描述高红移类星体中的尘埃性质和早期AGN宿主星系中活跃的恒星形成是至关重要的，这可能会对我们理解星系演化和黑洞质量与星系凸起之间的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在Z&GT；5为71个类星体收集这样的FIR测光。我们在这里申请一个博士后研究职位的资金，以领导该项目数据的分析、出版和分发。拟议的资金将使人们能够通过红外系统对覆盖其余框架的一整套光谱能量分布进行全面分析。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测辐射光度、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.