论文标题
一种无包装方法揭示了星系的AGN功率与从主序列偏移之间的连续关系
A binning-free method reveals a continuous relationship between galaxies' AGN power and offset from main sequence
论文作者
论文摘要
研究宿主星系的AGN功率与恒星形成率（SFR）之间关系的研究通常依赖于平均技术（例如堆叠）来整合非检测的信息。但是，平均值，尤其是手段可能会受到异常值的强烈影响，因此可以给出“典型”案例的误导性迹象。最近，许多研究通过以AGN功率（由AGN的2-10KeV亮度近似）来填充样品，并研究了SFR分布在这些垃圾箱之间的不同之处。这些垃圾箱阈值通常是弱动机的，而binning隐含地假设同一垃圾箱内的源具有相似（甚至相同）的特性。在本文中，我们研究了主机SFR的分布 - 相对于恒星形成主序列的轨迹（即$ r _ {\ rm ms} $） - 随着AGN功率的函数而连续更改。我们通过使用层次结构的贝叶斯模型来实现这一目标，该模型完全消除了AGN功率bin的需求。在这样做的过程中，我们发现了有力的证据表明，$ r _ {\ rm ms} $分布随着2-10kev X射线光度的变化而变化。结果表明，较高的x_ray发光度AGN与恒星形成过程的物理连接更紧密，至少在此处考虑的0.8 <z <z <z <z <1.2 $ redshift范围内。
Studies investigating the relationship between AGN power and the star formation rates (SFRs) of their host galaxies often rely on averaging techniques -- such as stacking -- to incorporate information from non-detections. However, averages, and especially means, can be strongly affected by outliers and can therefore give a misleading indication of the "typical" case. Recently, a number of studies have taken a step further by binning their sample in terms of AGN power (approximated by the 2-10keV luminosity of the AGN), and investigating how the SFR distribution differs between these bins. These bin thresholds are often weakly motivated, and binning implicitly assumes that sources within the same bin have similar (or even identical) properties. In this paper, we investigate whether the distribution of host SFRs -- relative to the locus of the star-forming main sequence (i.e., $R_{\rm MS}$) -- changes continuously as a function of AGN power. We achieve this by using a hierarchical Bayesian model that completely removes the need to bin in AGN power. In doing so, we find strong evidence that the $R_{\rm MS}$ distribution changes with 2-10keV X-ray luminosity. The results suggest that higher X_ray luminosity AGNs have a tighter physical connection to the star-forming process than lower X-ray luminosity AGNs, at least within the $0.8 < z < 1.2$ redshift range considered here.
