A scheme to unify low-power accreting black holes

Abstract

Abstract. We explore the evolution in power of black holes of all masses, and their associated jets, within the scheme of an accretion rate-dependent state transition. Below a critical value of the accretion rate all systems are assumed to undergo a transition to a state where the dominant accretion mode is optically thin and radiatively inefficient. In these significantly subEddington systems, the spectral energy distribution is predicted to be dominated by non-thermal emission from a relativistic jet whereas near-Eddington black holes will be dominated instead by emission from the accretion disk. Reasonable candidates for such a sub-Eddington state include X-ray binaries in the hard and quiescent states, the Galactic Center (Sgr A*), LINERs, FR I radio galaxies, and a large fraction of BL Lac objects. Standard jet physics predicts non-linear scaling between the optically thick (radio) and optically thin (optical or X-ray) emission of these systems, which has been confirmed recently in X-ray binaries. We show that this scaling relation is also a function of black hole mass and only slightly of the relativistic Doppler factor. Taking the scaling into account we show that indeed hard and quiescent state X-ray binaries, LINERs, FR I radio galaxies, and BL Lacs can be unified and fall on a common radio/X-ray correlation. This suggests that jet domination is an important stage in the luminosity evolution of accreting black hole systems.

The extension of variability properties in gamma-ray bursts to blazars

“…in BH systems should be intrinsically similar, which is supported by the so-called "fundamental plane" as found in XRBs and AGNs (e.g., Merloni et al 2003;Falcke et al 2004;Dong et al 2014). Despite the large discrepancy of the masses of AGNs and GRBs, several universal correlations have been found among the two types of objects, strengthc 0000 RAS ening this possibility.…”

Follow Up of GW170817 and Its Electromagnetic Counterpart by Australian-Led Observing Programmes

“…The compact radio emission detected by VLBA in the central region of NGC 4993 with a brightness temperature exceeding 10 6 K indicates the presence of a low-luminosity active galactic nucleus (LLAGN), allowing us to estimate the black hole mass using the fundamental plane of black hole activity (e.g. Plotkin et al 2012;Merloni, Heinz, & di Matteo 2003;Falcke, Körding, & Markoff 2004). The VLBA flux density was measured to be 0.22 ± 0.04 mJy at 8.7 GHz, which (assuming a flat spectral index) gives a 5-GHz radio luminosity of (2.1 ± 0.04) × 10 36 erg s −1 , while the X-ray luminosity as measured by SWIFT is 5.6 +2.4 −1.9 × 10 39 erg s −1 (Evans et al 2017).…”

Spectral state transitions of the Ultraluminous X-ray Source IC 342 X-1

“…To confirm or deny the existence of a self-absorbed compact jet and investigate whether a relationship known as the fundamental plane (FP) of black hole activity (Merloni et al 2003;Falcke et al 2004) could be used to estimate the mass of the BH, we obtained simultaneous radio and X-ray observations of X-1.…”