An outflow from the X-ray corona as the origin of millimeter emission from radio-quiet AGN
ORAL
Abstract
Recent observations of radio-quiet active galactic nuclei (RQAGN) have shown the presence of millimeter emission from within parsec scales of the central black hole, whose origin remains unknown. We argue that the mm emission comes from a spatially extended region that is connected to the compact X-ray corona via magnetic fields. We present an analytic model scaled to corona values in which electrons from multiple heights along an extended conical outflow shape the mm emission. We demonstrate this model's plausibility using a general relativistic magneto-hydrodynamic (GRMHD) simulation of a thin accretion disc as a case study. We find that the 100 GHz emission originates from within <104 gravitational radii (rg) of the central black hole, though the projected distance from the black hole can be as low as 50rg depending on the line-of-sight. Our model predicts a flat emission spectrum Fν∼const and a mm-to-X-ray luminosity ratio Lmm/LX∼10-4, consistent with observations. These quantities depend weakly on the underlying electron distribution function and black hole mass. Our model highlights the need to study continual dissipation along the outflow to connect the X-ray- and mm-emitting regions.
*Support for this work was provided by NASA through the NASA Hubble Fellowship grant \#HF2-51555 awarded by the Space Telescope Science Institute under contract NAS5-26555. GM is supported by a Canadian Institute of Theoretical Astrophysics (CITA) postdoctoral fellowship and acknowledges support from the Simons Collaboration on Extreme Electrodynamics of Compact Sources (SCEECS). An award of computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) and ASCR Leadership Computing Challenge (ALCC) programs under award AST178. This research used resources of the Oak Ridge Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC05-00OR22725. ML was supported by the John Harvard, ITC and NASA Hubble Fellowship Program fellowships, and NASA ATP award 80NSSC22K0817.DG is supported by the Research Foundation--Flanders (FWO) Senior Postdoctoral Fellowship 12B1424N.
