Title: Deciphering Radio Emissions from Accretion Disk Winds in Radio-Quiet Active Galactic Nuclei.
Authors: Tomoya Yamada, Nobuyuki Sakai, Yoshiyuki Inoue, Tomonari Michiyama
Unraveling the origins of radio emissions from radio-quiet active galactic nuclei (RQ AGNs) remains a pivotal challenge in astrophysics. One potential source of this radiation is the shock interaction between AGN disk winds and the interstellar medium (ISM). To understand this phenomenon, we construct a spherical, one-zone, and self-similar expansion model of shock structure between ultra-fast outflows (UFOs) and the ISM. We then calculate the energy density distribution of non-thermal electrons by solving the transport equation, considering diffusive shock acceleration as the acceleration mechanism and synchrotron and inverse Compton cooling as the cooling mechanisms. Based on the derived energy distribution of non-thermal electrons, we model the radio synchrotron spectrum of shocked ISM. For the 15 nearby RQ AGNs hosting UFOs, we investigate shocked ISM parameters required to model their observed radio spectra, based on X-ray observations and measured UFO velocities. Radio spectra of 11 out of 15 nearby RQ AGNs would be explained by the AGN disk wind model. This is a compelling indication that shock interactions between AGN disk winds and the ISM could indeed be the source of their radio emissions. The typical predicted source size and magnetic field strength are several 100 pc and 0.1 mG, respectively. We also discuss whether our prediction can be tested by future radio observations.
も参照してください
- Our paper on the coronal cosmic-ray energy budget in AGNs is accepted by PASJ.
- Our paper on cosmic rays in cosmological filaments is accepted by Universe.
- Our paper on multi-epoch X-ray spectral analysis of Cen A is accepted by PASJ.
- Our paper on Millimeter Time Variability in the Gamma-Ray Detected Seyfert Galaxy GRS 1734-292 is accepted by ApJ.
- Our paper on gamma-ray emission in NGC 4151 is accepted by PASJ.