The fundamental plane of black hole activity for quiescent sources

Abstract

AbstractIn this work, we construct a sample of black hole X‐ray binaries (BH XRBs), low‐luminosity active galactic nuclei (LLAGNs), and FR Is with wider distribution of Eddington ratios and re‐explore their fundamental plane of BH activities, that is, . We find that the quiescent BH sources follow a similar fundamental plane (ξX ∼ 0.6) with sub‐Eddington BH sources very well, while the strong radio sources (e.g., FR Is) follow a steeper fundamental plane (ξX ∼ 1.30). We also find that the radio–X‐ray correlation of quiescent BH sources are still on the extension of sub‐Eddington BH sources and the strong radio sources follow a steeper correlation (ξX ∼ 1.30). The results are consistent with recent observations in BH XRBs. It is predicted that the X‐ray emissions of both sub‐Eddington BH sources and quiescent BH sources originate from radiatively inefficient accretion mode, while the X‐ray emissions of strong radio sources dominantly originate from the jet.