论文标题
中子恒星z源GX中的反相关滞后5-1：Astrosat的观点
Anti-Correlated lags in a Neutron star Z source GX 5-1: AstroSat's View
论文作者
论文摘要
我们使用SXT和LAXPC Energy Bands Astrosat上的SXT和LAXPC Energy Bands报告了中子恒星低质量X射线二进制二进制的互相关函数研究。我们首次在GX 5-1中首次报告了软X射线能带（0.8-2.0 KEV，SXT）和硬X射线能带（10-20 KEV和16-40 KEV，LAXPC）之间的滞后，并在水平分支中检测到了几万到数百秒的顺序。我们将它们解释为积聚光盘内部区域的重新调整时间尺度。我们使用了各种两个组件和三成分光谱模型来展开光谱，并观察到表现出水平分支振荡变化的软和硬分量通量的变化。据观察，假定的Bbody组分是由NS上方的边界层起源的，也发现与检测到滞后的HBO变化有所不同。假设滞后是由于电晕尺寸的变化，我们限制了15-55 km的构成区域的大小。我们注意到采用其他模型后，构成区域的大小相似，并表明，电晕的整体大小必须达到几十公里的顺序，以解释滞后，HBO变化和各自的频谱变化。在一项案例研究中，注意到BL大小随GX 5-1的增加而增加，从HB的顶部到上顶点。
We report the cross-correlation function studies of a Neutron star low mass X-ray binary, a Z source GX 5-1 using SXT and LAXPC energy bands onboard AstroSat. For the first time, we report the lag between soft (0.8-2.0 keV, SXT) and hard X-ray energy bands (10-20 keV and 16-40 keV, LAXPC) in GX 5-1 and detected lags of the order of a few tens to hundreds of seconds in the Horizontal branch. We interpreted them as the readjustment time scale of the inner region of the accretion disc. We used various two components and three-component spectral models to unfold the spectra and observed the changes in soft and hard component fluxes which were exhibiting Horizontal Branch Oscillation variations. It was observed that the bbody component assumed to be originating from the boundary layer over the NS, was also found to vary along with the HBO variation where lags were detected. We constrained the size of the Comptonizing region of the order 15-55 km assuming that lags were due to variation in the size of the corona. We noticed a similar size of the Comptonizing region after employing other models and suggest that the overall size of corona must be of the order of a few tens of km to explain the lags, HBO variation, and respective spectral variations. In a case study, it was noted that the BL size increases as GX 5-1 vary from the top of the HB to the upper vertex.
