Seminar
The nuclear infrared emission of low-luminosity active galactic nuclei

Abstract

Low-luminosity AGN (LLAGN; LINERs and low-luminosity Seyferts) are present in numerous nearby galaxies and are often suggested to be the "missing link" between bright AGN and "normal", quiescent systems. Their accretion physics appear to differ from those of higher-luminosity AGN, and their place in the AGN unified scheme is not yet clear. Mid-IR observations promise new constraints on the accretion mechanisms and obscuring medium in LLAGN. However, their mid-IR emission remains almost completely unexplored at the high angular resolution needed to separate the weak nucleus from the host galaxy. I will show the results of an exploratory imaging study of ~20 LLAGN using Michelle and T-ReCS on the Gemini telescopes. Combined with Spitzer spectroscopy and high-resolution multi-wavelength information, the data establish, for the first time, the general nuclear IR properties of these objects. There are some hints that the obscuring torus disappears at low AGN luminosities, and we are also able to provide "dust-free" candidates for detailed study of the disk and jets.