Doyee’s Title: Analysis of Quasar Outflows Found in Ultraviolet Spectra

Quasars can affect their surrounding environment through a process known as active galactic nucleus (AGN) feedback, through which the quasar can curtail the formation of stars, regulate the evolution of its host galaxy, and affect its surrounding environment in other ways. One possible mechanism for this process is a quasar’s outflow, which can be observed as blueshifted absorption troughs in the quasar’s spectrum. With enough kinetic power, an outflow can contribute to AGN feedback, regulating star formation and host galaxy evolution. Analyzing the troughs of outflows found in ultraviolet spectra of quasars, observed both from the ground and in space, can reveal their physical characteristics, as well as their potential ability to contribute to feedback effects.

David’s Title: Exploring Ultra-Compact X-Ray Binaries with Reflection Modeling

Low mass X-ray binaries (LMXBs) are X-ray sources which contain a compact object such as a black hole (BH) or neutron star (NS) accreting material from a stellar companion. A subclass of LMXB called ultra compact X-ray binaries (UCXBs) contain a degenerate stellar companion such as a white dwarf (WD), resulting in a much shorter orbital period. We study one UCXB candidate and one verified UCXB using a process called reflection modeling, wherein the X-ray spectrum is modeled with components representing both direct emission and emission that is reprocessed by the accretion disk. This process can allow us to better understand the geometry and behavior of accreting systems, with UCXBs probing high energy accretion on some of the smallest size scales.