X-Ray Constraint on the Location of the AGN Torus in the Circinus Galaxy
X-Ray Constraint on the Location of the AGN Torus in the Circinus Galaxy
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DOI：
10.3847/1538-4357/abf0a2
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发表时间：
2021-03
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影响因子：
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通讯作者：
R. Uematsu;Y. Ueda;A. Tanimoto;T. Kawamuro;K. Setoguchi;S. Ogawa;S. Yamada;H. Odaka
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作者：
R. Uematsu;Y. Ueda;A. Tanimoto;T. Kawamuro;K. Setoguchi;S. Ogawa;S. Yamada;H. Odaka
活动星系核（AGN）中的模糊“环面”的位置仍然是一个悬而未决的问题。来自环面的X射线荧光线的线宽，特别是Fe Kα，携带着关于线发射区域半径的关键信息。利用XCLUMPY，一个X射线cluquetorus模型，我们开发了一个现实的模型，从AGN环面的发射线轮廓，我们考虑到线加宽由于开普勒运动围绕黑洞。然后，我们将更新后的模型应用于朱雀，XMM-牛顿，核光谱望远镜阵列和钱德拉观测到的圆规星系的最佳宽带光谱（3-100千电子伏），包括0.62 MS钱德拉/HETG数据。我们确认，环是康普顿厚（氢柱密度沿着赤道平面），几何薄（环角宽度），观察边缘（倾角），并有超太阳丰度（倍太阳）。同时分析Chandra/HETG的一阶、二阶和三阶谱，考虑到Fe Kα线发射区的空间范围，我们将环面的内半径限制为引力半径的倍，或黑洞质量为（1.7 ± 0.3）× 106 M Ω。这比根据尘埃升华半径估算的结果小三倍左右，这表明环的尘埃区内侧是由无尘气体组成的。
The location of the obscuring “torus” in an active galactic nucleus (AGN) is still an unresolved issue. The line widths of X-ray fluorescence lines originating from the torus, particularly Fe Kα, carry key information on the radii of line-emitting regions. Utilizing XCLUMPY, an X-ray clumpy torus model, we develop a realistic model of emission line profiles from an AGN torus where we take into account line broadening due to the Keplerian motion around the black hole. Then, we apply the updated model to the best available broadband spectra (3–100 keV) of the Circinus galaxy observed with Suzaku, XMM-Newton, Nuclear Spectroscopic Telescope Array, and Chandra, including 0.62 Ms Chandra/HETG data. We confirm that the torus is Compton-thick (hydrogen column density along the equatorial plane is ), geometrically thin (torus angular width ), viewed edge-on (inclination ), and has supersolar abundance ( times solar). Simultaneously analyzing the Chandra/HETG first-, second-, and third-order spectra with consideration of the spatial extent of the Fe Kα line-emitting region, we constrain the inner radius of the torus to be times the gravitational radius, or for a black hole mass of (1.7 ± 0.3) × 106 M ⊙. This is about three times smaller than that estimated from the dust sublimation radius, suggesting that the inner side of the dusty region of the torus is composed of dust-free gas.