Discovery of millimetre-wave excess emission in radio-quiet active galactic nuclei

摘要: The physical origin of radio emission in Radio Quiet Active Galactic Nuclei (RQ AGN) remains unclear, whether it is a downscaled version the relativistic jets typical Loud (RL) AGN, or originates from accretion disk. correlation between 5 GHz and X-ray luminosities RQ which follows $L_R = 10^{-5}L_X$ observed also stellar coronae, suggests an association both sources with disk corona. Observing AGN at higher (mm-wave) frequencies, where synchrotron self absorption diminished, smaller regions can be probed, key to exploring this association. Eight selected based on their high brightness variability, were 95 CARMA ATCA telescopes. All targets detected $1-10$ mJy level. Emission excess 95~GHz up $\times 7$ found respect archival low-frequency steep spectra, suggesting compact, optically-thick core superimposed more extended structures that dominate low frequencies. Though unresolved, fluxes imply optically thick source sizes $10^{-4}-10^{-3}$ pc, $\sim 10 - 1000$ gravitational radii. present lie tightly along $L_R$ (95 GHz) $10^{-4}L_X$ (2$-$10 keV) correlation, analogous coronae GHz, while RL are shown have / L_X$ ratios. observations argue simultaneous mm-wave monitoring features promising method for understanding coronal emission.