The Large Scale Structure of LINERs and Seyferts and Implications for   their Central Engines
  We discuss here the spatial clustering of Seyferts and LINERs and consequences for their central engines. We show that Seyferts are less clustered than LINERs, and that this difference is not driven by the morphology-density relation, but it is related to the difference in clustering as a function of level of activity in these systems and the amount of fuel available for accretion. LINERs, which are the most clustered among AGN, show the lowest luminosities and obscuration levels, and relatively low gas densities, suggesting that these objects harbor black holes that are relatively massive yet weakly active or inefficient in their accretion, probably due to the insufficiency of their fuel supply. Seyferts, which are weakly clustered, are very luminous, show generally high gas densities and large quantities of obscuring material, suggesting that in these systems the black holes are less massive but abundantly fueled and therefore accrete quickly and probably efficiently enough to clearly dominate the ionization. 
Anca Constantin and Michael S. Vogeley (Drexel University)