活动星系核统一模型与.ppt

Feb. 27, 2004 活动星系核统一模型和超大质量黑洞的形成与增长 张双南 清华大学物理系和天体物理中心 科学院高能所粒子天体物理重点实验室 Emission Line Spectra from Seyfert AGNs Unification scheme for type-I and type-II AGNs Investigation of the obscuring circumnuclear torus in the active galaxy Mrk231: Kloeckner et al., Nature, 2003 Sky deep surveys of Chandra and HST show that the fraction of type II AGN is decreasing with the hard X-ray luminosity. The inclination angle effect The inclination angle effect on type-II AGN fraction 考虑相对论效应对流强的修正 考虑相对论效应对光度的修正 考虑相对论效应对光度的修正 考虑相对论效应对能谱的修正 Anisotropy of inverse Compton scattering in corona A.Malizia ApJ 2003 589 L17 Inclination angle dependence of 2-10 keV spectral index Implications of this TAXI model TAXI model: Torus of Antonucci with X-ray Inclination-angle effects X-rays are produced primarily in accretion disk, but not in extended and near-spherical corona Many similarities in X-ray variabilities between X-ray binaries and AGNs suggest disk origin Several theoretical models suggest viable mechanisms for X-ray production from AGN disks, e.g., magnetic reconnection (like in the Sun), magnetic turbulent Comptonization Lack of broad Fe-K-alpha emission lines Accretion disk and the torus are co-aligned with each other Consistent with the model of Krolik and Begelman (1988) in which the torus feeds the black hole. Question to be answered: How does the torus form the accretion disk surrounding the black hole? Important correlations of SMBH mass with properties of galactic bulge No SMBH in M33? Merritt, et al, 2001, Science Unstable by design: Siemiginowska and Elvis, Nature, 1999 Lower stable branch: viscous heating balanced by cooling (BB radiation) Higher stable branch: viscous heating balanced by cooling (thermal Bremsstralung radiation) Middle unstable branch: UV photons strongly absorbed by hydrogen (ionization), cooling inefficient. Increate accretion rate Increase UV absorption Jumps between lower and higher branches Advantages of the instability model Previous proble