论文标题
中子恒星中的热辐射风低质量X射线二进制GX 13+1
The thermal-radiative wind in the neutron star low mass X-ray binary GX 13+1
论文作者
论文摘要
我们将观察到的高电离X射线吸收线在中子恒星二进制GX13+1中拟合，并完整模拟热辐射风。这使用辐射流体动力代码与蒙特卡洛辐射转移相结合，以计算来自氢和氦样铁和镍的观察到的线曲线，包括所有强的Kα和Kβ跃迁。风非常强，因为该物体的圆盘非常大，并且非常发光。 FeKα的吸收线非常饱和，因为离子柱很大，因此线等效宽度（EWS）敏感地依赖于速度结构。我们还模拟了在方位角和径向速度水平上的各种各向同性湍流。我们将这些模型拟合到最高分辨率Chandra三阶HETGS数据中的Fe XXV和XXVI吸收线。这些数据已经排除在径向速度的水平约为500 km/s处的湍流。单独的热辐射风预测的速度结构与观察到的轮廓相当匹配，在〜100 km/s的方位角速度水平上，额外的湍流上限。这对磁加速度的剩余贡献产生了严格的限制。
We fit the observed high ionisation X-ray absorption lines in the neutron star binary GX13+1 with a full simulation of a thermal-radiative wind. This uses a radiation hydrodynamic code coupled to Monte Carlo radiation transfer to compute the observed line profiles from Hydrogen and Helium-like iron and Nickel, including all strong Kα and Kβ transitions. The wind is very strong as this object has a very large disc and is very luminous. The absorption lines from Fe Kα are strongly saturated as the ion columns are large, so the line equivalent widths (EWs) depend sensitively on the velocity structure. We additionally simulate the lines including isotropic turbulence at the level of the azimuthal and radial velocities. We fit these models to the Fe xxv and xxvi absorption lines seen in the highest resolution Chandra third order HETGS data. These data already rule out the addition of turbulence at the level of the radial velocity of ~500 km/s. The velocity structure predicted by the thermal-radiative wind alone is a fairly good match to the observed profile, with an upper limit to additional turbulence at the level of the azimuthal velocity of ~100 km/s. This gives stringent constraints on any remaining contribution from magnetic acceleration.
