论文标题
高度模糊的活性银核NGC 4507的吸收变异性
Absorption Variability of the Highly Obscured Active Galactic Nucleus NGC 4507
论文作者
论文摘要
我们介绍了一项详细的研究，对使用四个核光谱望远镜阵列（Nustar）观察进行了高度模糊的活性星系NGC 4507，在2015年5月至8月之间进行了（总共约130 KS）。使用各种现象学和物理动机的圆环模型，我们探索了X射线源的特性以及遮盖物质的材料的特性。发现主要的X射线发射是不可变化的，表明在观测期间有稳定的积聚。我们发现，遮盖材料的赤道色谱柱密度为〜2 x 10^24 cm^-2，而视线柱密度为〜7-8 x 10^23 cm^-22。发现该来源被深埋，覆盖率〜0.85。我们观察到<35天的时间尺度上的视线线密度的可变性。发现Compton-Thick材料的覆盖因子与最近的X射线调查的结果一致。从视线线密度的变异性来看，我们估计可变吸收材料可能位于BLR或圆环中。
We present a detailed study of the highly obscured active galaxy NGC 4507, performed using four Nuclear Spectroscopic Telescope Array (NuSTAR) observations carried out between May and August in 2015 (~ 130 ks in total). Using various phenomenological and physically motivated torus models, we explore the properties of the X-ray source and those of the obscuring material. The primary X-ray emission is found to be non-variable, indicating a stable accretion during the period of the observations. We find the equatorial column density of the obscuring materials to be ~ 2 x 10^24 cm^-2 while the line of sight column density to be ~ 7 - 8 x 10^23 cm^-22. The source is found to be deeply buried with the torus covering factor ~ 0.85. We observe variability in the line-of-sight column density on a timescale of < 35 days. The covering factor of the Compton-Thick material is found to be ~ 0.35, in agreement with the results of recent X-ray surveys. From the variability of the line-of-sight column density, we estimate that the variable absorbing material is likely located either in the BLR or in the torus.
