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Abstract:

Abstract We investigate the relationship between disc winds, radio jets, accretion rates and black hole masses of a sample of ∼100k quasars at z ≈ 2. Combining spectra from the 17th data release of the Sloan Digital Sky Survey (SDSS) with radio fluxes from the 2nd data release of the Low Frequency ARray (LOFAR) Two-Meter Sky Survey (LoTSS), we statistically characterise a radio loud and radio quiet population using a two-component Gaussian Mixture model, and perform population matching in black hole mass and Eddington fraction. We determine how the fraction of radio loud sources changes across this parameter space, finding that jets are most efficiently produced in quasars with either a very massive central black hole (MBH > 109M⊙) or one that is rapidly accreting (λEdd > 0.3). We also show that there are differences in the blueshift of the $\textrm {C}\, \rm \small {IV}$ λ1549Å line and the equivalent width of the $\rm {He}\, \rm \small {II}$ λ1640Å line in radio loud and radio quiet quasars that persist even after accounting for differences in the mass and accretion rate of the central black hole. Generally, we find an anti-correlation between the inferred presence of disc winds and jets, which we suggest is mediated by differences in the quasars’ spectral energy distributions. The latter result is shown through the close coupling between tracers of wind kinematics and the ionising flux– which holds for both radio loud and radio quiet sources, despite differences between their emission line properties– and is hinted at by a different Baldwin effect in the two populations.

Abstract:

Abstract Scorpius X-1 (Sco X-1) is a neutron star X-ray binary in which the neutron star is accreting rapidly from a low mass stellar companion. At radio frequencies, Sco X-1 is highly luminous and has been observed to have jet ejecta moving at mildly relativistic velocities away from a radio core, which corresponds to the binary position. In this Letter, we present new radio observations of Sco X-1 taken with the Karl G. Jansky Very Large Array. Using a fast imaging method, we find that the 10 and 15 GHz data show a number of flares. We interpret these flares as the possible launching of fast jets (βΓ > 2), previously observed in Sco X-1 and called ultra-relativistic flows, and their interaction with slower moving jet ejecta. Using the period between successive flares, we find that it is possible for the fast jets to remain undetected, as a result of the fast jet velocity being sufficiently high to cause the jet emission to be beamed in the direction of the motion and out of our line of sight. Our findings demonstrate that the ultra-relativistic flows could be explained by the presence of fast jets in the Sco X-1 system.

Abstract:

Abstract Recent work revealed the existence of a galaxy ‘millimetre fundamental plane of black hole accretion’, a tight correlation between nuclear 1 mm luminosity, intrinsic 2 – 10 keV X-ray luminosity and supermassive black hole mass, originally discovered for nearby low- and high-luminosity active galactic nuclei. Here we use mm and X-ray data of 5 X-ray binaries (XRBs) to demonstrate that these stellar-mass black holes also lie on the mm fundamental plane, as they do at radio wavelengths. One source for which we have multi-epoch observations shows evidence of deviations from the plane after a state change, suggesting that the plane only applies to XRBs in the hard state, as is true again at radio wavelengths. We show that both advection-dominated accretion flows and compact jet models predict the existence of the plane across the entire range of black hole masses, although these models vary in their ability to accurately predict the XRB black hole masses.