X-ray changing-look active galactic nuclei(CL AGNs) are a subpopulation of AGNs,whose lineof-sight column densities increase/decrease within several years.The physical mechanism for the variation of column density is ...X-ray changing-look active galactic nuclei(CL AGNs) are a subpopulation of AGNs,whose lineof-sight column densities increase/decrease within several years.The physical mechanism for the variation of column density is unclear.We reduce the X-ray data from XMM-Newton and Nu STAR observations for a CL AGN NGC 1365 with strong variation of column densities.The X-ray spectrum quickly softens as the X-ray luminosity increases and optical-to-X-ray spectral index also increases as increasing of optical luminosity.These results support that NGC 1365 also undergoes strong spectral evolution as that recently suggested for the optically selected CL AGNs with reappearance/disappearance of broad emission lines.Therefore,the variation of column density may be driven by the variable disk winds during the strong evolution of disk/corona.展开更多
基金support from the National Natural Science Foundation of China (NSFC,Grant No.U1931203)support from NSFC (Grant Nos.12025303,11890693 and 11421303)+3 种基金the CAS Frontier Science Key Research Program (QYZDJ-SSWSLH006)the K.C.Wong Education Foundation.Z.C.He is supported by NSFC (Grant No.11903031)USTC Research Funds of the Double First-Class Initiative YD 3440002001supported by NSF grant AST1907290。
文摘X-ray changing-look active galactic nuclei(CL AGNs) are a subpopulation of AGNs,whose lineof-sight column densities increase/decrease within several years.The physical mechanism for the variation of column density is unclear.We reduce the X-ray data from XMM-Newton and Nu STAR observations for a CL AGN NGC 1365 with strong variation of column densities.The X-ray spectrum quickly softens as the X-ray luminosity increases and optical-to-X-ray spectral index also increases as increasing of optical luminosity.These results support that NGC 1365 also undergoes strong spectral evolution as that recently suggested for the optically selected CL AGNs with reappearance/disappearance of broad emission lines.Therefore,the variation of column density may be driven by the variable disk winds during the strong evolution of disk/corona.