Dartmouth Events

Abstract: Within the ΛCDM model, galaxies form within dark matter halos, and nearly all massive galaxies host a central supermassive black hole (SMBH). When actively accreting material, these SMBHs become active galactic nuclei (AGNs), releasing immense energy that can shape galaxy evolution. Blazars are an extreme AGNs subclass with relativistic jets oriented close to our line-of-sight, producing rapidly variable, generally jet-dominated emission. My dissertation uses observational data and empirical models to investigate AGNs from two perspectives. First, I present my optical spectropolarimetry study of blazars PKS 0637‑75 and PKS 1510‑089 to understand how jet orientation and dominant emission mechanisms affect polarization. Polarization measurements confirm SED modeling results: optical polarization and variability in PKS 0637‑75 are dominated by the accretion disk, while in PKS 1510‑089 both the disk and jet contribute. Second, I explore how host galaxy properties relate to AGN activity by determining the minimum stellar mass necessary for satellite galaxies hosting AGNs at 0.15 < z < 1.1, using both radio and X‑ray selection. The radio sample comes from LOFAR observations of the Boötes, ELAIS‑N1, and Lockman Hole fields, while the X‑ray sample uses archival Chandra data of the Boötes field. These projects reveal that a change in the dominant emission process (thermal vs. non‑thermal) affects continuum polarization (Project 1), and for the first time, we place constraints on the minimum stellar mass of satellite galaxies hosting radio‑selected (Project 2) and X‑ray‑selected (Project 3) AGNs.

Graduate Advisor: Professor Ryan Hickox 

Zoom Webinar Link: https://dartmouth.zoom.us/j/94653708302?pwd=Ob4xRTGZerTaS6LaPcNhFalbs6tnf2.1