| Interactions are crucial for galaxy formation and profoundly affect their evolution. However, our understanding of the impact of interactions on star formation and activity of the central supermassive black hole remains incomplete. In the canonical picture of the interaction process, these processes are expected to undergo a strong enhancement, but some recent studies have not found this prediction to be true in a statistically meaningful sense. This thesis uses a sample of local interactions observed from the ultraviolet to the far-infrared and a suite of N-body hydrodynamic simulations of interactions to examine the evolution of star formation, stellar mass, dust properties, and spectral energy distributions (SEDs) over the interaction sequence.;First, we present the SEDs of 31 interactions in 14 systems, which we fit with stellar population synthesis models combined with a thermal dust model. We examine the differences between mildly, moderately, and strongly interacting systems. The star formation rate (SFR), dust luminosity, and the 15-25 K dust component temperature increase as the interaction progresses from moderately to strongly interacting. However, the SFR per stellar mass remains constant across the interaction stages.;Second, we create 14 hydrodynamic simulations of isolated and interacting galaxies and calculate simulated photometry in 25 bands using the SUNRISE radiative transfer code. By comparing observed and simulated SEDs, we identify the simulation properties necessary to reproduce an interaction's SED. The best matches originate from simulated systems of similar stellar mass, infrared luminosities, dust mass, and SFR to the observed systems. Although an SED alone is insufficient to identify the interaction stage, strongly interacting systems preferentially match SEDs from times close to coalescence in the simulations.;Third, we describe a case study of a post-merger system, Fornax A, for which we constrain its parameters of its progenitors. Based on the excess dust mass in this elliptical galaxy, we estimate a spiral galaxy with a stellar mass of (1 - 6) x 1010 solar masses brought in ≈10% of Fornax A's current stellar mass. We describe the probable two-outburst history that created the radio lobes ∼0.4 Gyr ago and two cavities in the X-ray emission closer to the nucleus ∼0.1 Gyr ago. |
