Correlations of Active Galactic Nuclei with Microquasars

Correlations of active galactic nuclei (AGNs) with microquasars arediscussed based on the coexistence of the Blandford--Znajek (BZ) andmagnetic coupling (MC) processes (CEBZMC) in black hole (BH)accretion disk. The proportions of several quantities of BH systemsfor both AGNs and microquasars are derived by combining theobservational data with CEBZMC. It is shown that the square of themagnetic field at the BH horizon is inversely proportional to the BHmass, while the accretion rate of the disk is proportional to the BHmass. In addition, the very steep emissivity indexes from the recentXMM-Newton observations of the nearby bright Seyfert 1galaxy MCG-6-30-15 and the microquasars XTE J1650-500 are wellfitted by considering the MC effects on the disk radiation. Theseresults suggest strongly the correlations of AGNs with microquasars.