论文标题
用深度无线电观测来将类星体广播级的分数限制为$ z \ sim 6 $
Constraining the quasar radio-loud fraction at $z \sim 6$ with deep radio observations
论文作者
论文摘要
我们执行了一系列深karl G. Jansky非常大的阵列（VLA）S频段观测，以$ z \ sim6 $的21种类星体样本。新的观察结果将无线电连续排放的搜索扩展到最高的红移的光学微弱的类星体种群，并以$ 4400的$ 4400 \rmÅ$€$ 3 \ $ 3 \ times10^{11} {11} \ l _ {\ odot} $。我们报告了两个新的Radio-Loud类星体的检测：CFHQS J2242+0334（以下是$ Z = 5.88 $和CFHQS J0227 $ - $ 0605（$ 0605 $ -0605），$ z = 6.20 $，fl per fluniux $ z = 6.20 $，fl， 6.3 \μ\ rm jy $和$ 55.4 \ pm 6.7 \μ\ rm jy $。他们的无线电\替换{Loudness} {Loudness}估计分别为$ 54.9 \ pm 4.7 $和$ 16.5 \ pm 3.2 $。为了更好地限制无线电路的分数（RLF），我们将新测量结果与档案VLA L波段数据以及文献中的可用数据相结合，考虑到非潜在的上限和\ dreeted {and}可能的选择效果。最终派生的RLF为$ 9.4 \ pm 5.7 \％$，用于$ z \ sim6 $的光学选择的类星体。我们还将RLF与低红移时的类星体样品进行了比较，并在不同的类星体光度箱中检查RLF。由于样本量有限，光学上淡淡的物体的RLF仍然受到限制。我们的\ replect {result} {result}没有任何证据表明与红移相关。由于具有深度无线电观测的光学淡淡对象的样本量有限，因此与类星体紫外线/光光度的RLF进化趋势也没有明确的趋势。
We carry out a series of deep Karl G. Jansky Very Large Array (VLA) S-band observations of a sample of 21 quasars at $z\sim6$. The new observations expand the searches of radio continuum emission to the optically faint quasar population at the highest redshift with rest-frame $4400 \rm Å$ luminosities down to $3 \times10^{11} \ L_{\odot}$. We report the detections of two new radio-loud quasars: CFHQS J2242+0334 (hereafter J2242+0334) at $z=5.88$ and CFHQS J0227$-$0605 (hereafter J0227$-$0605) at $z=6.20$, detected with 3 GHz flux densities of $87.0 \pm 6.3 \ μ\rm Jy$ and $55.4 \pm 6.7 \ μ\rm Jy$, respectively. Their radio \replaced{loudness}{loudnesses} are estimated to be $54.9 \pm 4.7$ and $16.5 \pm 3.2$, respectively. To better constrain the radio-loud fraction (RLF), we combine the new measurements with the archival VLA L-band data as well as available data from the literature, considering the upper limits for non-detections and \deleted{and} possible selection effects. The final derived RLF is $9.4 \pm 5.7\%$ for the optically selected quasars at $z\sim6$. We also compare the RLF to that of the quasar samples at low redshift and check the RLF in different quasar luminosity bins. The RLF for the optically faint objects is still poorly constrained due to the limited sample size. Our \replaced{result}{results} show no evidence of significant quasar RLF evolution with redshift. There is also no clear trend of RLF evolution with quasar UV/optical luminosity due to the limited sample size of optically faint objects with deep radio observations.
