论文标题
磁盘截断的证据在黑洞二进制Maxi J1820+070的低积聚状态下nustar和XMM-Newton观察到的证据
Evidence for Disk Truncation at Low Accretion States of the Black Hole Binary MAXI J1820+070 Observed by NuSTAR and XMM-Newton
论文作者
论文摘要
我们从低积聚率（低于爱丁顿光度的1％）的Nustar和XMM-Newton观察到了Nustar和XMM-Newton的观察结果。我们检测到狭窄的Fe K $α$排放线，与以高积聚速率相比，黑洞二进制文件中通常存在的广泛而不对称的Fe K $α$线曲线。狭窄的线条具有较弱的相对论扩展，表明Fe K $α$线在较大的磁盘半径上产生。假设标准磁盘发射率的磁盘反射模型拟合会发现大磁盘截断半径（根据磁盘倾斜度，几十至几百个重力半径）。此外，我们检测到频率在$ 11.6 \ pm0.2 $ 〜mhz和$ 2.8 \ pm0.1 $ 〜mhz之间的频率之间变化的准周期振荡（QPO）。 QPO频率非常低，这表明，根据透镜 - 裂纹预动力模型，光学薄的构成区域的尺寸很大，这支持了从ISCO中退出的增生磁盘，并以低增生速率以对流为主的积聚流量取代。我们还讨论了一种替代积聚几何形状的可能性，即狭窄的fe k $α$线是由灯柱电晕产生的，高度很大。
We present results from NuSTAR and XMM-Newton observations of the new black hole X-ray binary MAXI J1820+070 at low accretion rates (below 1% of the Eddington luminosity). We detect a narrow Fe K$α$ emission line, in contrast to the broad and asymmetric Fe K$α$ line profiles commonly present in black hole binaries at high accretion rates. The narrow line, with weak relativistic broadening, indicates that the Fe K$α$ line is produced at a large disk radius. Fitting with disk reflection models assuming standard disk emissivity finds a large disk truncation radius (a few tens to a few hundreds of gravitational radii, depending on the disk inclination). In addition, we detect a quasi-periodic oscillation (QPO) varying in frequency between $11.6\pm0.2$~mHz and $2.8\pm0.1$~mHz. The very low QPO frequencies suggest a large size for the optically-thin Comptonization region according to the Lense-Thirring precession model, supporting that the accretion disk recedes from the ISCO and is replaced by advection-dominated accretion flow at low accretion rates. We also discuss the possibility of an alternative accretion geometry that the narrow Fe K$α$ line is produced by a lamppost corona with a large height illuminating the disk.
