James Madison University
Galaxies in the most underdense regions of the universe, the voids, must have different evolutionary histories than those in denser regions, the walls. This is mainly because of the expected huge difference in their rate of interactions, which is believed to affect the nuclear activity, and thus the growth process of galaxies and their central black holes. It is therefore important to determine the degree to which the void galactic nuclear activity compares to its counterpart in denser environments. I will present the results of a comparison of void and wall systems based on a variety of physical properties and near neighbor statistics, together with spatial clustering calculations, which provide empirical evidence that both small and large scale environment influence the interplay between nuclear supermassive black hole accretion and surrounding stellar activity, and thus the optically dominant power source. I will present these ideas in the context of a potential sequence in the lives of galaxies that suggests a transformation from star-forming via supermassive black hole accretion to quiescence, and show support for this scenario with new Chandra X-ray measurements.
Physics Bldg., room 401