Galaxies evolve over cosmic times in tandem with their larger environments (O(10 - 100 kpc)), which are influenced by galactic processes such as star formation and outbursts from an accreting supermassive black hole, also known as an Active Galactic Nucleus (AGN). The circumgalactic medium (CGM) is a reservoir of gas that surrounds all galaxies and is the recipient of galactic scale outflows, driven by either star formation or AGN activity, but also supplies the gas needed by the host galaxy to sustain star formation. The larger environment also impacts the CGM brightness, kinematics and metallicity, due to companion galaxy subhalos and mergers, thus offering a unique opportunity to observe the interplay between galactic and environmental processes.

Our multi-wavelength dataset of seven distant (z~2) radio-loud quasars allows us to investigate these interactions. Using data from W. M. Keck Observatory and archival data from the Very Large Array and ALMA radio facilities, and Hubble and Spitzer Space Telescopes, we observe outflows driven by the AGN, spatially resolved host galaxy emissions, CGM Ly-alpha, He II, and C IV emission and the influence of companion galaxies. We find evidence for a two component CGM model, where the inner CGM is directly influenced by the quasar host galaxy, whereas the outer CGM is influenced tidal interactions with companion galaxies and the turbulent motion of the gas.

Adaptive Optics (AO) has enabled higher angular resolution observations from the ground. Understanding the Point Spread Function (PSF) of the telescope limits our ability to disentangle phenomena at small angular resolution. A forward modelled PSF reconstruction represents the "pinnacle" of ground-based observational astronomy, since true knowledge of the observational PSF will reduce uncertainties in photometry and astrometry for all science cases. We investigate a PSF model for the NIRC2 instrument using AO telemetry data on Keck telescope and validate its performance using on-sky data. As a special application, we also investigate the PSF of the Corner Cube Retroreflectors left on the moon by Apollo astronauts, to investigate the performance degradation of these devices over the last 50 years due to dust deposition on their surfaces.

Star formation is key to the regulation of galactic environments. Studying the sites of ongoing star formation is therefore critical to understanding the evolution of galaxies over cosmic time. Integral Field Spectrographs (IFS) have allowed astronomers to probe the dynamical processes of galaxies at high redshift, z∼1-3, revealing unique kiloparsec-scale "clumps" of star formation. The relationships between clump size, luminosity, and velocity dispersion are particularly important to understanding clump formation and evolution. These relationships have been measured in a variety of studies but disagreement remains about their nature and possible evolution with redshift.To investigate the cause of these differences, I collected a comprehensive sample of clump observations across redshifts and developed a Bayesian Markov Chain Monte Carlo fitting routine to robustly explore the scaling relationships of star-forming regions. There is evidence of a break into two clump populations based on their star formation rate surface density with differences in slope due to either the formation mode or geometry of the clump and host galaxy disk, but there is added uncertainty from limited observations at small clump sizes. To address this limitation, I observed a sample of compact H II regions in the local starburst galaxy, IC 10, with the Keck Cosmic Web Imager IFS at the W. M. Keck Observatory. I found these H II regions are offset to higher luminosity and velocity dispersion for a given size. These H II regions do not appear to be virialized, and instead show evidence that they are young and expanding. Even in the most compact H II regions, warm gas pressure from photoinization heating provides the dominant contribution to outward pressure and expansion. Improvements in instrumentation are also key to improving studies of the characteristics and evolution of star-forming regions, as well as many other astronomical objects. Liger, an adaptive optics fed IFS and imager for Keck Observatory, will provide improvements in resolution, field of view, and wavelength coverage compared to current instruments. I have developed the mechanical design of three major components of the Liger imager and sequential spectrograph: the filter wheel; selectable cold pupil stop; and mounting stage for the imager detector and IFS pick-off mirrors.

This thesis studies actively accreting supermassive black holes (SMBH) known as quasars and their impact on the formation and evolution of massive galaxies. Theoretical work predicts that quasars are responsible for regulating the growth of the SMBH and its host galaxy. Winds driven by radiation pressure from the accretion disk and quasar jets are predicted to remove a substantial amount of gas from the host galaxy. Massive galaxies are observed to form the majority of their stars when the Universe was only 3.5 billion years old. During this epoch, the most massive SMBH already grew a substantial fraction of their mass. The SMBH is predicted to regulate the growth of the host galaxy during this co-evolutionary phase.

We have undertaken an extensive adaptive optics (AO) assisted integral field spectroscopy (IFS) survey of distant quasar host galaxies when the Universe was only 2.2-4.6 Gyr old. We conducted observations using the 10-meter W.M. Keck Observatory optical and infrared telescope. The survey aims to measure the gas-phase properties of quasar host galaxies such as metallicities, star formation rates, photoionization mechanisms, and search for galaxy-wide outflows potentially driven by the quasar. We detect outflows in all objects on scales from <1 kpc to 10 kpc. Half the outflows are consistent with being driven by a powerful energy-conserving shock, while the rest are either driven by radiation pressure or an isothermal shock. The outflows are the dominant source of gas depletion in these distant quasar host galaxies.

For the quasar 3C298, we have also conducted observations aimed at studying the molecular gas reservoir with the Atacama Large Millimeter Array (ALMA). In addition to detecting an ionized outflow in 3C298, we detect the first molecular outflow driven by a distant quasar. These observations show clear evidence for quasar driven outflows removing the molecular interstellar medium (ISM) through negative feedback.

The gas in the host galaxies is photoionized by a combination of O & B stars, the quasar, and radiative shocks. The chemical enrichment of the ISM is lower compared to the level observed in massive local galaxies. The quasar host galaxies appear to be under-massive relative to the mass of the SMBH based on local-scaling relations between the SMBH mass and galaxy mass. Substantial stellar growth and chemical enrichment are necessary if these galaxies are to grow and evolve into the most massive present-day elliptical galaxies.