Co-evolution between supermassive black holes (SMBH) and their host galaxies is observed via several relationships between SMBH properties and galaxy properties. However, the origin of these relationships is not well understood. Mergers are understood to be one cause, but in the last few years, simulations have shown that the majority of SMBH growth since redshift ~3 has occurred via secular processes (i.e., in the absence of mergers). Merger-free growth can be traced observationally via galaxy morphology, since disk-dominated galaxies with a small bulge to total stellar mass ratio have evolved via merger-free pathways since redshift ~2. Thus, by investigating active galactic nuclei (AGN, rapidly accreting SMBHs) in disk-dominated galaxies at low redshift, this merger-free growth can be investigated. 

The student will use observations made by various facilities and surveys (such as SDSS and DESI Legacy Surveys) to create samples of AGN in disk-dominated hosts. Since stellar dynamics are incredibly challenging to observe directly, requiring many on-sky observing hours, the student will use galaxy morphologies as tracers of these stellar dynamics with the aim of understanding the interplay between various morphological features and AGN presence. They will use python (and the comprehensive libraries within) to investigate the population level correlations and develop theories about this co-evolution from their results.

Häring N., Rix H.-W., 2004, ApJ, 604, L89
Kormendy J., Ho L. C., 2013, ARA&A, 51, 511
Simmons B. D., Smethurst R. J., Lintott C., 2017, MNRAS, 470, 1559
Martin G. et al., 2018, MNRAS, 476, 2801
McAlpine S., Harrison C. M., Rosario D. J., Alexander D. M., Ellison S. L., Johansson P. H., Patton D. R., 2020, MNAS, 494, 5713
Smethurst R. J. et al., 2023, MNRAS, 527, 10855
Martig M., Bournaud F., Croton D. J., Dekel A., Teyssier R., 2012, ApJ, 756, 26