College - Author 1
College of Science and Mathematics
Department - Author 1
Physics Department
Degree Name - Author 1
BS in Physics
Date
6-2026
Primary Advisor
Vardha Bennert, College of Science and Mathematics, Physics Department
Abstract/Summary
At the center of most massive galaxies, there is a supermassive black hole with a mass millions to billions of times that of the Sun. In some of these galaxies, so-called Active Galactic Nuclei (AGNs), the supermassive black hole is converting the gas that falls toward it into radiation energy, creating large amounts of luminosity. AGNs are composed of the central supermassive black hole, its accretion disk, and a region just outside, composed of fast-moving ionized gas clouds called the Broad Line Region (BLR). Using spectra obtained with NASA’s Infrared Telescope Facility, we use a technique known as reverberation mapping to study the BLR structure and photoionization of the AGN Mrk 1239. Most importantly, reverberation mapping results in a measurement of the black hole mass. Previous reverberation mapping studies were done in the optical – our study is uniquely in the near infrared. Our infrared campaign also allows for a direct comparison to measurements of the BLR completed by the GRAVITY/VLTI instrument using the same lines, minimizing systematic uncertainties. Such a comparison will put stronger constraints on the properties of the AGNs and may even open the door to measuring the Hubble constant, one of the most important values in cosmology. In this thesis, I will summarize observations and data reduction. The main result is the light curve for Mrk 1239, focusing on the broad lines Brackett γ and Paschen β. When comparing with optical light curves tracing the accretion disk variations, we can determine a time lag and thus the size of the BLR for the first time in the near-infrared.
URL: https://digitalcommons.calpoly.edu/physsp/241