论文标题
来自模拟IXPE数据的增生驱动毫秒脉冲星的中子星参数约束
Neutron star parameter constraints for accretion-powered millisecond pulsars from the simulated IXPE data
论文作者
论文摘要
我们已经模拟了在观察积聚驱动的毫秒脉冲星时，可以通过成像X射线极化探索器获得的X射线极化数据。我们估计了SAX J1808.4 $ - $ 3658的必要曝光时间，以便在所有能量通道集成的时间相关的Stokes概况中获得不同的精度。我们发现，测得的相对误差在很大程度上取决于观察者和排放热点的相对构型。 Stokes $ Q $和$ u $参数的最小相对错误的最小相对错误的改善，该函数的函数$ t $ scales为$ 1/\ sqrt {t} $，并且范围从30-90％的范围从200 ks的曝光时间到20-60％的20-60％的敞口时间（在500 ks in in 2 exeps bins中）。模拟数据还用于预测在仅建模$ q $和$ u $参数时，可以制作中子星的几何参数的准确测量值，而不是通量。我们发现，在我们考虑的大多数情况下，观察者的倾斜度和热点共纬度可以以优于10度的精度确定。当与X射线脉冲曲线的建模结合使用时，这些测量值可用于进一步限制中子星的质量和半径。
We have simulated the X-ray polarization data that can be obtained with the Imaging X-ray Polarimetry Explorer, when observing accretion-powered millisecond pulsars. We estimated the necessary exposure times for SAX J1808.4$-$3658 in order to obtain different accuracies in the measured time-dependent Stokes profiles integrated over all energy channels. We found that the measured relative errors depend strongly on the relative configuration of the observer and the emitting hotspot. The improvement in the minimum relative error in Stokes $Q$ and $U$ parameters as a function of observing time $t$ scales as $1/\sqrt{t}$, and spans the range from 30-90% with 200 ks exposure time to 20-60% with 500 ks exposure time (in case of data binned in 19 phase bins). The simulated data were also used to predict how accurate measurements of the geometrical parameters of the neutron star can be made when modelling only $Q$ and $U$ parameters, but not the flux. We found that the observer inclination and the hotspot co-latitude could be determined with better than 10 deg accuracy for most of the cases we considered. These measurements can be used to further constrain neutron star mass and radius when combined with modelling of the X-ray pulse profile.
