Chandra High-Resolution Spectroscopy of the Absorption-Line Features in the Low-Mass X-Ray Binary GX 13+1
Chandra High-Resolution Spectroscopy of the Absorption-Line Features in the Low-Mass X-Ray Binary GX 13+1
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低质量 X 射线双星 GX 13 1 中吸收线特征的钱德拉高分辨率光谱分析
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发表时间：
2004
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通讯作者：
K. Ebisawa
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作者：
Y. Ueda;H. Murakami;K. Yamaoka;T. Dotani;K. Ebisawa
我们给出了用Chandra HETGS对GX13+1的X射线光谱中高电离离子吸收线特征的高分辨光谱结果。我们解析了类氢Fe、Mn、Cr、Ca、Ar、S、硅、镁离子和类氦Fe离子的K-α吸收谱线。将福格特分布应用于这些光谱特征，我们发现负责吸收谱线的等离子体有显著的蓝移，约为460±70公里的S-1，经自行校正的流出速度为400公里的S-1，视线速度色散为490公里的S-1。等离子体被光致电离，电离参数为对数ξ≃4.14.7。推算出的质量外流速率为0.7×1018g S-1或更高，与由连续谱估算的质量吸积速率(1018g S-1)相当。这表明质量外流在决定吸积盘整体动力学过程中起着重要作用。我们考虑了一个简化的辐射驱动的圆盘风模型来解释外流的起源。我们的观测是由半径约为10~10-10~11厘米、密度≳为10~(13)厘米~(-3)的风解释的。
We present the results of high-resolution spectroscopy of absorption-line features of highly ionized ions in the X-ray spectra of GX 13+1 with the Chandra HETGS. We have resolved Kα absorption lines of hydrogen-like Fe, Mn, Cr, Ca, Ar, S, Si, and Mg ions and helium-like Fe ions. Applying the Voigt profile to these spectral features, we find that the plasma responsible for the absorption lines has a significant blueshift of 460 ± 70 km s-1, indicating an outflow velocity of ≈400 km s-1 corrected for the proper motion, with a line-of-sight velocity dispersion of 490 km s-1. The plasma is photoionized with an ionization parameter of log ξ ≃ 4.1-4.7. The inferred mass outflow rate is 0.7 × 1018 g s-1 or higher, comparable to the mass accretion rate (1018 g s-1) estimated from the continuum spectrum. This indicates that the mass outflow plays a significant role to determine the whole dynamics of the accretion disk. We consider a simplified radiation-driven disk wind model for the origin of the outflow. Our observations are explained by the wind originating from radii of ~1010-1011 cm with a density ≳1013 cm-3.