Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Physics and Astronomy Dept.


Dale Kocevski


An active galactic nucleus (AGN) occurs when the supermassive black hole at the center of the galaxy starts to grow. We still currently do not know what triggers AGN. Theories suggest that galaxy mergers could trigger AGNs, but past research has not been able to find a correlation between x-ray detected AGNs and disturbed galaxies. The present research looks specifically at AGN not detected in the x-ray, or obscured AGN. Using a newly updated IDL code, FAST, we were able to identify potential obscured AGN through spectral energy distribution (SED) modeling. We found a total of 526 obscured AGN in all CANDELS fields, all with the following properties: mass greater than 1010 Msolar, redshifts between 0.5 and 1.5, and a magnitude brighter than 24.5. Using visual classification, galaxies were labeled as either disturbed or undisturbed. Then using a simple binomial distribution, we found a slightly significant difference (σ = 2.18) between obscured AGN and a control group. In conclusion, we found that obscured AGN were slightly more disturbed than their non-AGN counterparts.


AGN, Black Holes, FAST, CANDELS, SED Modeling