Photometric Observations and Analysis of Active Galactic Nuclei
Authors:Haley Redinger, Lindsey Schlueter
Mentor:Carol Hood, Assistant Professor of Physics, Cal State University, San Bernardino
We present preliminary results in an ongoing project to determine the mass of active galactic nuclei (AGN) through reverberation mapping of photometric data. By measuring the variability of AGN in different filters, reverberation mapping is an attempt to observe the time difference between changes occurring close to the central black hole compared to when they occur further from the center. Measuring this lag time lets us calculate the size of the gas cloud region surrounding the central black hole, which is related to the mass of the AGN itself. Knowing the mass of the black hole helps in understanding the formations of and relationship between the black hole and the surrounding galaxy. We monitored four different active galactic nuclei during July and August 2013 using the 20-inch Cassegrain telescope at the Murillo Family Observatory at Cal State University, San Bernardino. Target objects were selected to have relatively bright apparent magnitudes and known narrow-line lag-times of less than thirty days, so any lags in variability would be observable during our campaign. We obtained multiple images of each object using broad-band filters I, R, V, and B. Raw images were reduced and stacked to increase the signal-to-noise-ratio of the target in each image to be used to perform photometric analysis. Continued observations using both broad- and narrow-band filters are planned.