论文标题
重新离世时期结束时的新无线电大声QSO
New Radio-Loud QSOs at the end of the Re-ionisation Epoch
论文作者
论文摘要
我们介绍了从无线电快速ASKAP Contairuum调查（RACS; 888 MHz）和光学/近红外暗能量调查（DES）的组合中选择高红色（$ Z \ GTRSIM5.7 $）无线电路（RL）Quasi-Stellar对象（QSO）候选者（QSO）。特别是，我们选择了六个候选人比$ s _ {\ rm 888MHz}> 1 $ mjy beam $^{ - 1} $和$ {\ rm mag}（z_ \ mathrm {des}}）<21.3 $ <21.3 $使用辍学技术（在$ i $ band）中。从这个样本中，我们能够确认两个来源的高$ z $ nature（$ z \ sim6.1 $），这些来源现在已成为当前最高的REDSHIFT RL QSO之一。基于我们的双子座/南部/转基因生物观测，这两个对象都显示出突出的$α$排放线。这表明这两个来源都可能是托管无线电飞机的弱排放线QSO，因此将进一步增强文献中最近发现的弱排放线QSO的潜在增加。但是，需要进一步的多波长观察来限制这些QSO及其相对论喷射的特性。从发现这两个来源的发现中，我们估计了红移范围内的RL QSO的空间密度$ 5.9 <z <6.4 $，为0.13 $^{+0.18} _ { - 0.09} $，并发现它基于我们对Blazar总体的当前知识的期望一致，高达$ z \ sim5 $。
We present the selection of high-redshift ($z\gtrsim5.7$) radio-loud (RL) quasi-stellar object (QSO) candidates from the combination of the radio Rapid ASKAP Continuum Survey (RACS; at 888 MHz) and the optical/near-infrared Dark Energy Survey (DES). In particular, we selected six candidates brighter than $S_{\rm 888MHz}>1$ mJy beam$^{-1}$ and ${\rm mag}(z_\mathrm{DES})<21.3$ using the dropout technique (in the $i$-band). From this sample, we were able to confirm the high-$z$ nature ($z\sim6.1$) of two sources, which are now among the highest-redshift RL QSOs currently known. Based on our Gemini-South/GMOS observations, neither object shows a prominent Ly$α$ emission line. This suggests that both sources are likely to be weak emission-line QSOs hosting radio jets and would therefore further strengthen the potential increase of the fraction of weak emission-line QSOs recently found in the literature. However, further multiwavelength observations are needed to constrain the properties of these QSOs and of their relativistic jets. From the discovery of these two sources, we estimated the space density of RL QSOs in the redshift range $5.9<z<6.4$ to be 0.13$^{+0.18}_{-0.09}$ and found it to be consistent with the expectations based on our current knowledge of the blazar population up to $z\sim5$.
