Program: GN-2007A-Q-93

We propose NIRI/Michelle imaging observations of 14 LINER galaxies to search for signatures of dusty tori in their nuclei. X-ray and other observations of these and many other LINERs provide convincing evidence that a significant fraction of them harbor accreting supermassive black holes, and as such they may represent the transition stage between classical AGN and quiescent objects. If so, they provide an opportunity to probe whether AGN unification models extend to very low AGN luminosities. A number of observational and theoretical lines of evidence suggest that dusty circumnuclear tori, the cornerstone of AGN unified schemes, do not exist in low-luminosity systems like these. We will search for the IR emission expected from dust in close proximity to and reprocessing radiation from the AGN in these galaxies and compare the IR SEDs to those of Seyfert galaxies. The spatial resolution attainable for ground-based thermal-IR images, which we will combine with archival HST near-IR data, is necessary to ensure that measurements of the SED of the putative tori are not compromised by extended emission from stars and dust not directly associated wth the torus.