The physical fundamental plane of black hole activity: revisited

Abstract

The correlation between the jet power and accretion disk luminosity is investigated for active galactic nuclei (AGNs) and black hole X-ray binaries (BHXBs) from the literature. The power-law correlation index is steep ($\mu \sim$ 1.0--1.4) for radio loud quasars and the `outliers' track of BHXBs, and it is flatter ($\mu \sim$ 0.3--0.6) for radio loud galaxies and the standard track of BHXBs. The steep-index groups are mostly at higher accretion rates (peaked at Eddington ratio $>$ 0.01) and the flatter-index groups are at relatively low accretion rates (peaked at Eddington ratio $<$ 0.01), implying that the former groups could be dominated by the inner disk accretion of black hole, while the jet in latter groups would be a hybrid production of the accretion and black hole spin. We could still have a fundamental plane of black hole activity for the BHXBs and AGNs with diverse (maybe two kinds of) correlation indices. It is noted that the fundamental plane of black hole activity should be referred to the correlation between the jet power and disk luminosity or equivalently to the correlation between jet power, Eddington ratio and black hole mass, rather than the jet power, disk luminosity and black hole mass.Comment: 7 pages, 5 figures, accepted for publication in Astrophysics & Space Science