Heavy obscuration in X-ray weak AGNs
Heavy obscuration in X-ray weak AGNs
复制标题
X 射线弱 AGN 中的重遮蔽
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
G. Zamorani
中科院分区：
文献类型：
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作者：
R. Maiolino;M. Salvati;L. Bassani;M. Dadina;R. Ceca;G. Matt;G. Risaliti;G. Zamorani
我们目前的观测，在0.1-100 keV的光谱带的8个塞弗特2星系，通过BeppoSAX获得。这些来源是根据其[OIII]光发射线通量选择的，以避免对pc尺度上的遮蔽的偏差。所有的来源都被发现了。它们都是弱X射线发射体，其中大多数在6.4 ~ 7 keV（EW > 500 eV）处具有突出的铁谱线，并且具有平坦的连续谱，这表明沿着我们的视线方向存在严重的遮蔽（在大多数情况下NH> 10^25 cm^-2）。这些结果1）提供了进一步的证据，有利于统一的情况下，和2）表明，2型活动星系核的平均遮蔽度很可能是远远高于以往的X射线调查推断。这些发现对X射线背景的合成具有重要意义。
We present observations in the 0.1-100 keV spectral band of 8 Seyfert 2 galaxies, obtained by means of BeppoSAX. These sources were selected according to their [OIII] optical emission line flux, to avoid biases against obscuration on the pc scale. All sources were detected. All of them are weak X-ray emitters, and most of them are characterized by prominent iron lines at 6.4-7 keV (EW > 500 eV) and by a flat continuum, indicative of heavy obscuration along our line of sight (N_H > 10^25 cm^-2 in most cases). These results 1) provide further evidence in favor of the unified scenario, and 2) indicate that the average obscuration of type 2 AGNs is very likely much higher than deduced by former X-ray surveys. These findings have important implications for the synthesis of the X-ray background.