The Jet-Disk Coupling of Seyfert Galaxies from a Complete Hard X-ray Sample

Abstract

We analyze the jet-disk coupling for different subsamples from a complete hard X-ray Seyfert sample to study the coupling indices and their relation to accretion rate. The results are: (1) the power-law coupling index ranges from nearly unity (linear correlation) for radio loud Seyferts to significantly less than unity for radio quiet ones. This decline trend of coupling index also holds from larger sources to compact ones; (2) the Seyferts with intermediate to high accretion rate (Eddington ratio λ ∼ 0.001 to 0.3) show a linear jet-disk coupling, but it shallows from near to super Eddington ( λ ∼ 0.3 to 10), and the former is more radio loud than the latter; (3) the Seyfert 1s are slightly steeper than the Seyfert 2s, in the jet-disk correlation. In the linear coupling regime, the ratio of jet efficiency to radiative efficiency ( η / ε ) is nearly invariant, but in low accretion or super accretion regime, η / ε varies with λ in our model. We note that a radio-active cycle of accretion-dominated active galactic nuclei would be: from a weaker jet-disk coupling in λ 0 . 001 for low luminosity Seyferts, to a linear coupling in 0 . 001 λ 0 . 3 for radio-loud luminous Seyferts and powerful radio galaxies/quasars, and to a weaker coupling in 0 . 3 λ 10 ones.

Keywords

• Seyfert galaxies
• accretion rate
• jet power
• jet-disk coupling