论文标题
中子恒星低质量X射线二进制4U 1636-536中X射线频谱中盘式反射的证据
Evidence of disc reflection in the X-ray spectrum of the neutron star low mass X-ray binary 4U 1636-536
论文作者
论文摘要
我们提出了Atoll Source 4U〜1636-536的宽带光谱分析，该分析以$ \ sim92 $ ks为\ nustar {}观察到。在此观察期间，发现该来源处于低亮度状态，$ 3-79 \ kev {} $ l_ {3-79 kev} =（1.03 \ pm0.01）\ times 10^{37} $ ergs/s，假设6 kpc的距离。在此观察过程中，我们已经确定并删除了十二型I X射线爆发，以研究持续的发射。连续体由$γ\ sim1.9 $，$ kt_ {e} \ sim28 \ kev {} $和$ kt_ {s} {s} \ sim0.9 \ kev {} $进行很好的描述。 \ nustar {}数据揭示了圆盘反射的明确签名，一条大量宽的Fe-K发射线（约合5-8美元\ kev {} $）和相应的反射hump（左右$ 15-30 \ kev {} $）。我们已经使用两个相对模糊的反射模型对数据进行了建模。反射模型的两个家族都均在ISCO之前均均均均截断了内盘半径。我们发现内部光盘被$ r_ {in} =（3.2-4.7）\; r_ {isco} $（$ \ simeq16-24 \，r_ {g} \：\：\ text {or} {or} \：36-54 $ km）的内部光盘被截断。此内盘半径表明中子星磁场强度为$ b \ leq2.0 \ times10^{9} $G。
We present a broadband spectral analysis of the atoll source 4U~1636-536 observed for $\sim92$ ks with \nustar{}. The source was found to be in a low-luminosity state during this observation with $3-79 \kev{}$ X-ray luminosity of $L_{3-79 keV}=(1.03\pm0.01)\times 10^{37}$ ergs/s, assuming a distance of 6 kpc. We have identified and removed twelve type-I X-ray bursts during this observation to study the persistent emission. The continuum is well described by a thermal Comptonization model {\tt nthcomp} with $Γ\sim1.9$, $kT_{e}\sim28 \kev{}$, and $kT_{s}\sim0.9\kev{}$. The \nustar{} data reveal a clear signature of disc reflection, a significantly broad Fe-K emission line (around $5-8\kev{}$), and the corresponding reflection hump (around $15-30\kev{}$). We have modeled the data with two relativistically blurred reflection models. Both families of reflection models prefer truncated inner disc radii prior to the ISCO. We find that the inner disc is truncated with an inner radius of $R_{in}=(3.2-4.7)\;R_{ISCO}$ ($\simeq16-24\,R_{g}\: \text{or}\: 36-54$ km). This inner disc radius suggests that the neutron star magnetic field strength is $B\leq2.0\times10^{9}$ G.
