论文标题
通过fe k $α$线轮廓测量的部分积聚盘掩星的中子星半径与质量比率
Neutron Star Radius-to-mass Ratio from Partial Accretion Disc Occultation as Measured through Fe K$α$ Line Profiles
论文作者
论文摘要
我们提出了一种新方法，通过通过恒星本身利用内部盘的部分掩盖，来测量弱磁性，圆盘上的中子恒星的半径与质量比（R/M）。这种掩盖烙印在X射线线轮廓上具有独特的特征，并且有望存在于低于〜65度的倾斜度下的低质量X射线二进制系统中。我们分析了对良好候选系统4U 1636-53的NUSTAR观察，发现当前仪器的X射线光谱由于信号到噪声不足而不太可能单一挑出掩盖功能。基于一组广泛的模拟，我们表明，未来一代的大区域X射线检测器可以在一系列倾斜范围内测量R/M至〜2÷3％精度。这就是半径确定的精度，即对超严重物质状态的方程进行严格的限制所需的精度，它代表了其他方法在将来也旨在实现的目标。
We present a new method to measure the radius-to-mass ratio (R/M) of weakly magnetic, disc-accreting neutron stars by exploiting the occultation of parts of the inner disc by the star itself. This occultation imprints characteristic features on the X-ray line profile that are unique and are expected to be present in low mass X-ray binary systems seen under inclinations higher than ~65 degrees. We analyse a NuSTAR observation of a good candidate system, 4U 1636-53, and find that X-ray spectra from current instrumentation are unlikely to single out the occultation features owing to insufficient signal-to-noise. Based on an extensive set of simulations we show that large-area X-ray detectors of the future generation could measure R/M to ~2÷3% precision over a range of inclinations. Such is the precision in radius determination required to derive tight constraints on the equation of state of ultradense matter and it represents the goal that other methods too aim to achieve in the future.
