UCLA

It is believed that supermassive black holes (\mbh\ $\sim 10^6M_{\odot}- 10^{9}M_{\odot}$) in the center of galaxies are a vital component of galaxy evolution. This idea is driven by two observations: (i) black hole (BH) masses are tightly correlated to host galaxy properties in local quiescent galaxies, and (ii) BH accretion and star formation histories track one another closely. These two observations suggest that the growth of accreting BHs is intimately connected to that of their host galaxies. However, the origin and physical mechanism remains unknown and is an active area of astrophysical research.

The goal of this dissertation is twofold: (i) characterize the structure and kinematics of the broad emission line region (BLR) to better understand the central regions of accreting BHs and (ii) improve the way BH mass measurements are calibrated across cosmic time. While both goals aim to provide insight into the role BHs play in galaxy evolution, the latter is most relevant for studies that probe the origin of the BH scaling relations via characterization across redshift.

In this dissertation, I model the H$\beta$ BLR of nine Active Galactic Nuclei (AGN) observed during the Lick AGN Monitoring Project (LAMP) 2016 reverberation mapping campaign and investigate whether there are any luminosity-dependent trends in the structure and kinematics of the \H$\beta$ BLR. Then, I combine the LAMP 2016 modeling results with previous LAMP reverberation mapping campaigns and search for a way to improve how BH masses are calibrated across cosmic time. Finally, I expand on the initial development and testing of \textsc{caramel-gas}, which aims to model the gas density field of the BLR to model multiple emission lines simultaneously, e.g., H$\alpha$ and H$\beta$, and learn about the surroundings of active BHs. However, further testing and development of \textsc{caramel-gas} beyond the work presented in this thesis is required before achieving this goal. Overall, future reverberation mapping campaigns with sufficient data quality and variability are needed to confirm the results presented in this thesis.