论文标题
异步极性的宽带X射线研究：CD IND
A broadband X-ray study of the asynchronous polar: CD Ind
论文作者
论文摘要
提出了对异步极性源CD IND获得的XMM-Newton和Nustar观测值获得的X射线数据的同时宽带分析。柔软的0.3-3.0 keV带中的自旋折叠曲线显示出偶尔狭窄的倾角叠加的单个宽阔的驼峰状结构，表明具有复杂的内在吸收器的单杆积聚模型。在3 keV上方的折叠式弯曲中缺乏强烈的调制表明，在整个自旋相中，来自震后区域（PSR）相应区域（PSR）的发射仍保持不变。宽带光谱以三组分吸收的等离子体发射模型和吸收的同质冷却流模型进行建模，这两者都以相似的统计显着性符合数据。在具有等效列密度$ \ sim7 \ times10^{22} \; \ text {cm}^{ - 2} $的光谱中，部分覆盖吸收器的存在很明显。在光谱中检测到了强电离氧K $_α$线排放。我们注意到自旋阶段0.75-1.05期间的光谱变异性，当总体吸收器的色谱柱密度大大增加时（从$ \ sim 1 \ sim 1 \ times 10^{20} {20} \; \ \ \ text {cm}^{ - 2} $ to $ \ $ \ sim 9 \ sim 9 \ sim 9 \ sim 10^{20} {20} {20} {20} {20} \ \ text {cmm}我们至少需要三个血浆温度来描述PSR的多温特性。电击温度$ \ sim 43.3 _ { - 3.4}^{+3.8} $ keV，由冷却流模型的高温表示，暗示着白矮人的质量为$ \ sim 0.87^{+0.04} _ { - 0.04} _ { - 0.03} \; m _; m _ {\ m _ {\ odot} $。铁K $_α$线复合物显示出强烈的HE样和弱中性荧光线。我们无法明确检测到光谱中康普顿反射的存在，这可能很小，表示高度的冲击高度。
A simultaneous broadband analysis of X-ray data obtained with XMM-Newton and NuSTAR observatories for the asynchronous polar source CD Ind is presented. The spin folded lightcurve in soft 0.3-3.0 keV band shows single broad hump-like structure superimposed with occasional narrow dips, indicating a single-pole accretion model with a complex intrinsic absorber. Lack of strong modulation in folded lightcurve above 3 keV reveals that emission from corresponding zone of post-shock region (PSR) remains in view throughout the spin phase. The broadband spectrum is modelled with a three-component absorbed plasma emission model and absorbed isobaric cooling flow model, both of which fit the data well with similar statistical significance. Presence of partial covering absorber is evident in the spectra with equivalent column density $\sim7\times10^{22}\;\text{cm}^{-2}$ and a covering fraction of $\sim 25\%$. Strong ionised oxygen K$_α$ line emission is detected in the spectra. We notice spectral variability during spin phase 0.75-1.05, when there is a considerable increase in column density of overall absorber (from $\sim 1 \times 10^{20}\;\text{cm}^{-2}$ to $\sim 9 \times 10^{20}\;\text{cm}^{-2}$). We required at least three plasma temperatures to describe the multi-temperature nature of the PSR. The shock temperature $\sim 43.3_{-3.4}^{+3.8}$ keV, represented by the upper temperature of the cooling flow model, implies a white dwarf mass of $\sim 0.87^{+0.04}_{-0.03}\;M_{\odot}$. The iron K$_α$ line complex shows a strong He-like and a weak neutral fluorescence line. We could not unambiguously detect the presence of Compton reflection in the spectra, which is probably very small and signifying a tall shock height.
