标题： 计算类星体-射电源对以推导毫央克级射电光度函数和聚类强度至红移 z=3.5 显示英文标题

标题： Counting quasar--radio source pairs to derive the millijansky radio luminosity function and clustering strength to z=3.5

摘要： 我们应用了一种互相关技术，从 NRAO VLA 天空巡天（NVSS）推断出$S>3$毫焦耳每球面立体角的射电星族函数（RLF），直至$z\sim3.5$。 我们测量了 $\Sigma$在光谱确认类星体周围的射电源过剩密度。 $\Sigma$与类星体距离处射电源的空间密度以及两个样本之间的聚类强度有关，因此，其中一个的已知情况会限制另一个。 在简单假设下，我们发现$\Phi\propto (1+z)^{3.7\pm0.7}$直到$z\sim2$。 在更高的红移之上，演化速度减缓，我们限制了演化指数为 $<1.01$ ($2\sigma$)。 这种行为与之前的研究者在RLF的亮端发现的行为几乎完全相同，这可能表明我们在观察同一类群体。 这表明NVSS主要由一个单一的群体主导；最有可能的是与高激发冷态吸积相关的射电源。 相反，通过采用先前建模的RLF，我们可以限制高红移射电源的聚类，并找到一个与 $r_0=15.0\pm 2.5$ Mpc 至 $z\sim3.5$ 一致的聚类强度。 这与低红移的类星体以及一些明亮FRII源聚类测量结果不一致。 这种行为更符合本地宇宙中较低光度射电星系的聚类。 我们的结果显示，主导我们样本的高激发系统，在所有采样的红移中都宿主在最巨大的星系中。 显示英文摘要

摘要： We apply a cross-correlation technique to infer the $S>3$mJy radio luminosity function (RLF) from the NRAO VLA sky survey (NVSS) to $z\sim3.5$. We measure $\Sigma$ the over density of radio sources around spectroscopically confirmed quasars. $\Sigma$ is related to the space density of radio sources at the distance of the quasars and the clustering strength between the two samples, hence knowledge of one constrains the other. Under simple assumptions we find $\Phi\propto (1+z)^{3.7\pm0.7}$ out to $z\sim2$. Above this redshift the evolution slows and we constrain the evolution exponent to $<1.01$ ($2\sigma$). This behaviour is almost identical to that found by previous authors for the bright end of the RLF potentially indicating that we are looking at the same population. This suggests that the NVSS is dominated by a single population; most likely radio sources associated with high-excitation cold-mode accretion. Inversely, by adopting a previously modelled RLF we can constrain the clustering of high-redshift radio sources and find a clustering strength consistent with $r_0=15.0\pm 2.5$ Mpc up to $z\sim3.5$. This is inconsistent with quasars at low redshift and some measurements of the clustering of bright FRII sources. This behaviour is more consistent with the clustering of lower luminosity radio galaxies in the local universe. Our results indicate that the high-excitation systems dominating our sample are hosted in the most massive galaxies at all redshifts sampled.