2017MNRAS.466.3353R

It has been well established in the past decades that the central black hole masses of galaxies correlate with dynamical properties of their harbouring bulges. This notion begs the question of whether there are causal connections between the active galactic nucleus (AGN) and its immediate vicinity in the host galaxy. In this paper, we analyse the presence of circumnuclear star formation in a sample of 15 AGN using mid-infrared observations. The data consist of a set of 11.3 µm polycyclic aromatic hydrocarbon emission and reference continuum images, taken with ground-based telescopes, with sub-arcsecond resolution. By comparing our star formation estimates with AGN accretion rates, derived from X-ray luminosities, we investigate the validity of theoretical predictions for the AGN-starburst connection. Our main results are: (i) circumnuclear star formation is found, at distances as low as tens of parsecs from the nucleus, in nearly half of our sample (7/15); (ii) star formation luminosities are correlated with the bolometric luminosity of the AGN (L_AGN) only for objects with L_AGN >= 10⁴² erg s^–1; (iii) low-luminosity AGNs (L_AGN < 10⁴² erg s^–1) seem to have starburst luminosities far greater than their bolometric luminosities.