Stephen A. Gregory, Professor, Associate Director of IFA, Director of Capilla Peak Observatory
Research Interests:
My main area of interest is in the field of large-scale structures in the Universe. I was part of the group that first discovered Cosmic Voids and proved the existence of Superclusters of Galaxies. When we look at the early Universe, for example with the Cosmic Microwave Background Radiation, we see a striking degree of uniformity. However, when we look at the present-day Universe, we see massive clumps of matter and vast reaches of emptiness. These large structures are the fossils that will eventually tell us how the Universe evolved to its present state. My current work centers on two specific aspects of superclusters. First, in the western portions of the Perseus Supercluster, I have shown that the active Seyfert galaxies all fall into one of three filaments; why do Seyferts avoid the other two? Second, the galaxies appear to be aligned. How is it that one galaxy knows what direction its neighbors point? There are many aspects of these studies that are ideal for graduate students to work on.