论文标题
QSO的星形形成率
The star-formation rates of QSOs
论文作者
论文摘要
我们使用来自Herschel-Atlas的Spire数据，在0.5 <z <z <2.65红移范围内检查了5391个光学选择QSO的样品的Far-Ir性质。我们将样品拆分为74个亮度 - 红移箱的网格，并计算每个箱中的平均光边光谱分布（SED）。通过将固有的AGN模板归一化为AGN光学功率（在5100A时），我们将总红外发射（L_IR; 8-1000UM）分解为AGN（L_IR，AGN）和星形成部分（L_IR，L_IR，SF）。我们发现，AGN对L_IR的贡献随着AGN功率的函数而增加，这表现为平均QSO SED中“ Far-ir Bump”的降低。我们注意到L_IR，SF与AGN功率无关。 AGN宿主星系的平均星星形成速率（SFRS）仅是红移的函数，在Z〜0的〜6 msun/yr范围为Z〜2.6时<200 msun/yr的平台。我们的结果表明，Far-Ir发射作为SFR的代理的准确性随着AGN发光度的增加而降低。我们表明，在任何给定的红移下，都可以通过一个简单的模型来解释红外亮度（无论是单色还是总数）和AGN功率（在光学或X射线中）之间观察到的趋势，该模型是两个组成部分的总和：（a）与AGN POWER和（b）无效的AGN和AGN的恒星形态相关的红外排放，直接与AGN供电，并直接使用AGN，AGN供您使用。
We examine the far-IR properties of a sample of 5391 optically selected QSOs in the 0.5<z<2.65 redshift range down to log[nuLnu,2500 (erg/s)]>44.7, using SPIRE data from Herschel-ATLAS. We split the sample in a grid of 74 luminosity-redshift bins and compute the average optical-infrared spectral energy distribution (SED) in each bin. By normalising an intrinsic AGN template to the AGN optical power (at 5100A) we decompose the total infrared emission (L_IR; 8-1000um) into an AGN (L_IR,AGN) and star-forming component (L_IR,SF). We find that the AGN contribution to L_IR increases as a function of AGN power which manifests as a reduction of the `far-IR bump' in the average QSO SEDs. We note that L_IR,SF does not correlate with AGN power; the mean star formation rates (SFRs) of AGN host galaxies are a function of redshift only and they range from ~6 Msun/yr at z~0 to a plateau of <200 Msun/yr at z~2.6. Our results indicate that the accuracy of far-IR emission as a proxy for SFR decreases with increasing AGN luminosity. We show that, at any given redshift, observed trends between infrared luminosity (whether monochromatic or total) and AGN power (in the optical or X-rays) can be explained by a simple model which is the sum of two components: (A) the infrared emission from star-formation, uncorrelated with AGN power and (B) the infrared emission from AGN, directly proportional to AGN power in the optical or X-rays.
