论文标题
根据其光谱能量分布
Evidence of under-developed torus and broad-line region of weak emission line quasars based on their spectral energy distribution
论文作者
论文摘要
为了揭示在光学选择的“弱排放线样”（WLQ）子集中弱排放线的主要原因，我们研究了欠发达的宽线区域（BLR）的可能性。为此，我们通过分别使用SDS和明智的光度观测值对61个WLQ的光谱能量分布（SED）进行了建模。 SED拟合包括各种排放组件，包括来自Dusty Torus的亮度（$ L_ {TOR} $）。为了与正常类星体进行比较，我们使用了一个对照样本，用于在发射红移和SDSS R波段中匹配的每个WLQ的55 QSO。基于我们对$ L_ {tor} $的测量，我们发现在wlqs w.r.t中，$ 42 \ pm2 $ \％的ir-luminosity减少了普通QSO的控制样本。使用$ l_ {tor} $/$ l_ {bol} $作为圆环覆盖因子的度量（$ cf_ {tor} $），我们发现WLQS覆盖因子的下降类似，其$ CF_ {tor} $分布均显着不同。带有ks-test $ p_ {null} $ $ 4.27 \ times 10^{ - 14} $的普通QSO。由于预计AGN中的尘土和BLR覆盖因子的顺序将相似，因此我们的结果表明，WLQ中的BLR欠发达，可能是其发射线弱点的主要原因。结果，我们的分析基于进化场景在AGN的早期阶段为WLQS的模型提供了支持。
To unravel the dominant cause of the weak emission line in a subset of optically selected radio-quiet 'weak emission line quasars' (WLQs), we have investigated the possibility of an underdeveloped broad line region (BLR). For this, we have modeled spectral energy distributions (SED) of 61 WLQs by using their optical and infrared (IR) photometric observations from SDSS and WISE respectively. SED fit consists of various emission components, including the luminosity from the dusty torus ($L_{tor}$). For comparison with the normal quasar, we have used a control sample of 55 QSOs for each WLQs matching in emission redshift and SDSS r-band. Based on our measurement of $L_{tor}$, we found a decrement of $42\pm2$\% in IR-luminosity in WLQs w.r.t the control sample of normal QSOs. Using $L_{tor}$/$L_{bol}$ as the measure of torus covering factor ($CF_{tor}$) we found a similar decrement in WLQs covering factor, with their $CF_{tor}$ distribution being significantly different w.r.t. the normal QSOs with a KS-test $P_{null}$ of $4.27 \times 10^{-14}$. As dusty torus and BLR covering factors are expected to be of a similar order in AGN, our results suggest that the BLR in the WLQs is underdeveloped and could be a dominant cause of the weakness of their emission line. As a result, our analysis gives support to the models of WLQs based on the evolution scenario being in an early stage of AGNs.
