论文标题

弱线类星体的代表性样本的敏感Chandra覆盖范围:揭示全部X射线特性

Sensitive Chandra coverage of a representative sample of weak-line quasars: revealing the full range of X-ray properties

论文作者

Ni, Q., Brandt, W. N., Luo, B., Garmire, G. P., Hall, P. B., Plotkin, R. M., Shemmer, O., Timlin III, J. D., Vito, F., Wu, J., Yi, W.

论文摘要

我们提出了代表性样本中弱线类星体(WLQ)的更深的Chandra观察结果,该样品先前具有有限的X射线约束,并执行X射线光度分析,以揭示WLQS的X射线特性的全范围。这些代表性样本中包含的32个WLQ中只有5个在这些观察后仍未被检测到X射线,并且堆叠分析表明,这5个平均X射线弱点为> 85。样本中的WLQ之一是已知具有极端X射线变化状态的X射线变化,SDSS j1539+3954的差异很大,X射线均具有极大的变化。在其余框架中〜3个月。对于X射线通量变化的短时尺度,$ \ gtrsim $ 9的倍数进一步支持厚度磁盘和流出(TDO)模型,该模型旨在解释WLQ的X射线和多波长特性。 WLQ的X射线到光学特性的总体分布表明,TDO具有X射线发射区域的平均覆盖率,TDO的圆柱密度范围从$ N _ {\ rm H} $ h} $ \ sim $ \ sim 10^{23-24}〜{23-24}〜{\ rm cm cm} $ cm} $ \ gtrsim 10^{24}〜{\ rm cm}^{ - 2} $,在WLQ中导致不同级别的吸收和康普顿反射(和/或散射)。

We present deeper Chandra observations for weak-line quasars (WLQs) in a representative sample that previously had limited X-ray constraints, and perform X-ray photometric analyses to reveal the full range of X-ray properties of WLQs. Only 5 of the 32 WLQs included in this representative sample remain X-ray undetected after these observations, and a stacking analysis shows that these 5 have an average X-ray weakness factor of > 85. One of the WLQs in the sample that was known to have extreme X-ray variability, SDSS J1539+3954, exhibited dramatic X-ray variability again: it changed from an X-ray normal state to an X-ray weak state within ~ 3 months in the rest frame. This short timescale for an X-ray flux variation by a factor of $\gtrsim$ 9 further supports the thick disk and outflow (TDO) model proposed to explain the X-ray and multiwavelength properties of WLQs. The overall distribution of the X-ray-to-optical properties of WLQs suggests that the TDO has an average covering factor of the X-ray emitting region of ~ 0.5, and the column density of the TDO can range from $N_{\rm H}$ $\sim 10^{23-24}~{\rm cm}^{-2}$ to $N_{\rm H}$ $\gtrsim 10^{24}~{\rm cm}^{-2}$, which leads to different levels of absorption and Compton reflection (and/or scattering) among WLQs.

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