A unified scenario of black hole X-ray binary states with jets

Jets from a black hole X-ray binary (BHXB) could be powered by extracting energy either from a magnetized accretion flow, or from the spin of the black hole. Here we report a new method to explore if both the steady jets in the low-hard state (LHS) and transient jets in the transition state of black hole X-ray binaries (BHXBs) are primarily accretion-powered. In our theoretical magnetohydrodynamic calculations, we assume an advective accretion scenario to explain the accretion-jet processes in both the transition state and the LHS. Based on the estimates of the ratio of `mass flow rate into the jet' to `mass accretion rate' (${\dot M_j}/{\dot M}$), we theoretically predict that the disc efficacy to launch transient jets is less than that for steady jets. We tentatively verify this theoretical finding using the ratio of radio$-$to$-$X-ray luminosities ($L_{\rm R}/L_{\rm X}$) for several BHXBs, where $L_{\rm R}$ and $L_{\rm X}$ are simultaneous measured, corresponding to each of steady jet and transient jet. Our study tentatively suggests that both steady and transient jets in BHXRBs could primarily be accretion powered, indicating a possible unified scenario of two BHXB states with jets. Our work may have a wider implication to understand the physics of accretion-jet mechanism in different types of accreting objects, such as radio loud active galactic nuclei.