论文标题
黑洞X射线二进制Maxi J1820+070的光谱研究与Astrosat和Nustar
A spectral study of the black hole X-ray binary MAXI J1820+070 with AstroSat and NuSTAR
论文作者
论文摘要
Maxi J1820+070是一种新发现的瞬态黑洞X射线二进制，它显示了几个光谱和时间特征。在这项工作中，我们分析了所有三个同时观察Astrosat上X射线仪器的宽带X射线光谱，以及Nustar的X射线仪器，以及在2018年3月的最大J1820+070的硬性状态下观察到的Nustar的X射线谱。 xillvercp，我们实现了适合Astrosat和Nustar光谱的合理且一致的拟合。最佳拟合模型建议使用低温光盘（$ kt _ {\ rm in} \ sim 0.3 $ keV），铁过度（$ a _ _ {\ rm fe} \ sim 4-5 $ solar），短的灯 - 灯 - post corona高度（$ h \ $ h \ life sim sim sim sim sims 8 r _ r _ rm g} $ g} $ corcor { E} \ SIM 115-150 $ KEV）。添加第二个组合成分会导致明显更好的拟合度，第二个组合组件的$ kt _ {\ rm e} $是$ \ sim 14-18 $ kev。我们来自具有相似源状态的两个不同卫星的独立观测结果的结果表明，均无中等的电晕，温度降低归因于高度的增加。此外，利用Astrosat的更广泛的能量覆盖范围，我们估计黑洞质量为$ 6.7-13.9 \ m _ {\ odot} $，与文献中报道的独立测量相一致。
MAXI J1820+070 is a newly discovered transient black hole X-ray binary, which showed several spectral and temporal features. In this work, we analyse the broadband X-ray spectra from all three simultaneously observing X-ray instruments onboard AstroSat, as well as contemporaneous X-ray spectra from NuSTAR, observed during the hard state of MAXI J1820+070 in March 2018. Implementing a combination of multi-colour disc model, relativistic blurred reflection model relxilllpCp and a distant reflection in the form of xillverCp, we achieve reasonable and consistent fits for AstroSat and NuSTAR spectra. The best-fit model suggests a low temperature disc ($kT_{\rm in} \sim 0.3$ keV), iron overabundance ($A_{\rm Fe} \sim 4-5$ solar), a short lamp-post corona height ($h \lesssim 8 R_{\rm g}$), and a high corona temperature ($kT_{\rm e} \sim 115-150$ keV). Addition of a second Comptonisation component leads to a significantly better fit, with the $kT_{\rm e}$ of the second Comptonisation component being $\sim 14-18$ keV. Our results from independent observations with two different satellites in a similar source state indicate an inhomogeneous corona, with decreasing temperature attributed to increasing height. Besides, utilising the broader energy coverage of AstroSat, we estimate the black hole mass to be $6.7-13.9 \ M_{\odot}$, consistent with independent measurements reported in the literature.
