标题： 磁星耀斑和结构化吸积盘日冕的喷流 显示英文标题

标题： Magnetic flares and outflows from structured accretion disc coronae

摘要： 我们提出一个关于吸积盘上方磁性结构日冕的模型。 在最短的时间尺度上，空间和时间相关联的日冕耀斑可以解释 Seyfert 星系中观测到的 X 射线时间和光谱变化。 特别是，功率密度谱、通量-光谱指数和通量-方差相关性自然地被该模型所解释。 更显著的光谱变化（即 GBHC 中的状态转换）与在更长时间尺度上变化的参数有关，例如吸积率、日冕强度或内盘的几何结构。 在标准 Shakura--Sunyaev 吸积盘理论框架下，我们讨论为什么在低吸积率下能量占主导地位的日冕是驱动强大 MHD 驱动外流的理想场所。 然后，如果外流是辐射无效的，那么整个源也是辐射无效的，即使没有吸积流动力学中的吸积效应。 这可能是 LLAGN 和 GBHC 在低/硬状态下的另一种情景，并可能对理解宇宙的吸积历史产生影响。 显示英文摘要

摘要： We present a model for magnetic structured coronae above accretion discs. On the shortest timescales, spatially and temporally correlated coronal flares can explain X-ray temporal and spectral variability observed in Seyfert galaxies. In particular, power density spectra, flux-spectral index and flux-variance correlations are naturally accounted for by the model. More dramatic spectral variations (i.e. state transitions in GBHC) are associated with parameters varying on longer timescales, such as accretion rate, coronal strength or geometry of the inner disc. In the framework of the standard Shakura--Sunyaev accretion disc theory, here we discuss why energetically dominant coronae at low accretion rates are ideal sites for launching powerful MHD driven outflows. Then, if the outflow is radiatively inefficient, then so is the source overall, even without advection being relevant for the dynamics of the accretion flow. This could be an alternative scenario for LLAGN and GBHC in their low/hard state, and may have consequences for our understanding of the accretion history of the universe.