论文标题
超紧凑型中子星X射线二进制4U 1916-053中的红移内盘大气和瞬时吸收器
A Redshifted Inner Disk Atmosphere and Transient Absorbers in the Ultra-Compact Neutron Star X-ray Binary 4U 1916-053
论文作者
论文摘要
超紧凑型X射线二进制（UCXB）中的非常小的积聚磁盘是研究磁盘积聚和流出的特殊实验室。我们报告了三组新的（250 ks总计）和档案（50 ks）Chandra/hetg观察到“浸入”中子星X射线X射线二进制二进制二进制4U 1916 $ -053，其轨道时期为$ P \ simeq 50 $〜分钟。我们发现，所有三个光谱中的大部分吸收都起源于磁盘氛围，由$ v \ simeq 220-220-290 $ $ $ $ \ text {km} $ $ \ $ \ $ \ text {s}^s}^{ - 1} $对应于radius of $ r \ r \ r \ sim 1200 $ nim/sim/c} c} c}这种转移以最强，最高度离子化的线（Si XIV和Fe XXVI）的形式存在，其显着性为5 $σ$。浸入事件期间观察到的吸收线（通常与最外面的磁盘相关联）相反，没有显示速度偏移，并且是局部休息标准，这表明红移是内部磁盘大气的固有的，而不是由于银河系中的径向运动或踢。在两个光谱中，也有证据表明，更强烈的红移组件将与$ r \ sim 70 $ $ gm/{c}^{2} $的磁盘气氛相对应；该组件在3 $σ$级别上很重要。最后，在一个频谱中，我们找到了圆盘风的证据，其蓝色移位为$ v = {-1700}^{+1700} _ { - 1200} $ $ $ $ \ text {km $ \ $ $ $ \ text {s}}^{ - 1} $。如果真实，则这条风需要磁性驱动。
The very small accretion disks in ultra-compact X-ray binaries (UCXBs) are special laboratories in which to study disk accretion and outflows. We report on three sets of new (250 ks total) and archival (50 ks) Chandra/HETG observations of the "dipping" neutron-star X-ray binary 4U 1916$-$053, which has an orbital period of $P\simeq 50$~minutes. We find that the bulk of the absorption in all three spectra originates in a disk atmosphere that is redshifted by $v\simeq 220-290$ $\text{km}$ $\text{s}^{-1}$, corresponding to the gravitational redshift at radius of $R \sim 1200$ $GM/{c}^{2}$. This shift is present in the strongest, most highly ionized lines (Si XIV and Fe XXVI), with a significance of 5$σ$. Absorption lines observed during dipping events (typically associated with the outermost disk) instead display no velocity shifts and serve as a local standard of rest, suggesting that the redshift is intrinsic to an inner disk atmosphere and not due to radial motion in the galaxy or a kick. In two spectra, there is also evidence of a more strongly redshifted component that would correspond to a disk atmosphere at $R \sim 70$ $GM/{c}^{2}$; this component is significant at the 3$σ$ level. Finally, in one spectrum, we find evidence of disk wind with a blue shift of $v = {-1700}^{+1700}_{-1200}$ $\text{km}$ $\text{s}^{-1}$. If real, this wind would require magnetic driving.
