Faculty Mentor: Paul Wiita
Students: Paolo DiLorenzo, Mitchell Revalski, & Dan Sprague
During the summer of 2012 Paolo Di Lorenzo, Daniel Sprague, and Mitchell Revalski conducted research in the field of active galactic nuclei under the advisement of Dr. Paul Wiita. The purpose of this research project was to search for periodic luminosity variations in a class of active galactic nuclei known as “Blazars” using the Kepler space satellite. The Kepler satellite is used to search for exoplanets (planets outside of our solar system); however, it has the advantage of nearly uninterrupted viewing over long time scales since it is a satellite in an earth trailing orbit. We can use this nearly continuous and high precision photometric data to carefully study how galaxies with active cores vary in brightness over time. In particular, we hope to learn more about the physics of accretion disks (material encircling the central supermassive black hole) as well as relativistic jets beamed outward from these central sources. These relativistic jets emanating from the core are pointed close to our line of sight (similar to staring right into a flashlight), and gives rise to the term “Blazar”. Evidence of quasi-periodic variations would help to better support certain models of relativistic jet physics and accretion disk theory.
In the past evidence has surfaced that these periodic variations exist, however for the targets which we researched during MUSE, we found little evidence of this behavior. Our group work consisted primarily of correcting the data for instrumental effects so it could be processed properly. In addition we created our own programs using a variety of languages to evaluate the data. The primary tools used to evaluate the corrected and uncorrected data were power spectral densities, structure functions, and periodograms. Future work in this area includes processing data which is not yet available for the same target objects, as well as looking at data available for other objects of the same type.