Millimeter-band variability of the radio-quiet nucleus of NGC7469

TL;DR

This study presents short-term 95 GHz radio monitoring of the radio-quiet AGN NGC7469, revealing rapid variability comparable to X-ray fluctuations, supporting a common origin linked to the accretion disk corona.

Contribution

First high-cadence 95 GHz variability study of NGC7469, demonstrating rapid flux changes and their correlation with X-ray variability, indicating a shared physical origin.

Findings

NGC7469 varies by a factor of two within 4-5 days at 95 GHz

Radio variability amplitude is comparable to X-ray variability

Radio and X-ray emissions likely originate from the same physical process

Abstract

We report short-cadence monitoring of a radio-quiet Active Galactic Nuclei (AGN), NGC7469, at 95 GHz (3 mm) over a period of 70 days with the CARMA telescope. The AGN varies significantly ($\pm3\sigma$ from the mean) by a factor of two within 4-5 days. The intrinsic 95 GHz variability amplitude in excess of the measurement noise (10%) and relative to the mean flux is comparable to that in the X-rays, and much higher than at 8.4 GHz. The mm-band variability and its similarity to the X-ray variability adds to the evidence that the mm and X-ray emission have the same physical origin, and are associated with the accretion disk corona.