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We present observations of the molecular gas in the nuclear environment ofthree prototypical low luminosity AGN (LLAGN), based on VLT/SINFONI AO-assistedintegral-field spectroscopy of H2 1-0 S(1) emission at angular resolutions of~0.17". On scales of 50-150 pc the spatial distribution and kinematics of themolecular gas are consistent with a rotating thin disk, where the ratio ofrotation (V) to dispersion (sigma) exceeds unity. However, in the central 50pc, the observations reveal a geometrically and optically thick structure ofmolecular gas (V/sigma<1 and N_H>10^{23} cm^{-2}) that is likely to beassociated with the outer extent of any smaller scale obscuring structure. Incontrast to Seyfert galaxies, the molecular gas in LLAGN has a V/sigma<1 overan area that is ~9 times smaller and column densities that are in average ~3times smaller. We interpret these results as evidence for a gradualdisappearance of the nuclear obscuring structure. While a disk wind may not beable to maintain a thick rotating structure at these luminosities, inflow ofmaterial into the nuclear region could provide sufficient energy to sustain it.In this context, LLAGN may represent the final phase of accretion in currenttheories of torus evolution. While the inflow rate is considerable during theSeyfert phase, it is slowly decreasing, and the collisional disk is graduallytransitioning to become geometrically thin. Furthermore, the nuclear region ofthese LLAGN is dominated by intermediate-age/old stellar populations (withlittle or no on-going star formation), consistent with a late stage ofevolution.

The central molecular gas structure in LINERs with low luminosity AGN: evidence for gradual disappearance of the torus