Physical Sciences and Mathematics Commons^™

Probing The Galactic Agb Population Through Infrared And Sio Maser Emission, Megan O. Lewis

Physics & Astronomy ETDs

Stars on the Asymptotic Giant Branch (AGB) are of low to intermediate mass and have reached the end stages of stellar evolution. The mass-loss that stars undergo at this phase enshrouds the central star in a circumstellar envelope (CSE) that redistributes most of the stellar light into the infrared (IR) regime of the spectrum. In the CSEs of oxygen-rich AGB stars molecules including SiO form, and under certain conditions maser emission from SiO can make AGB stars bright beacons at radio frequencies (e.g., 43 and 86 GHz). SiO masers are ideal observational probes of AGB sources, providing data on their …

Circumstellar Sio Masers In The Bulge Asymmetries And Dynamical Evolution Survey, Michael Cullen Stroh

Physics & Astronomy ETDs

The Bulge Asymmetries and Dynamical Evolution (BAaDE) project aims to explore the complex structure of the inner Galaxy and Galactic Bulge, by using the 43 GHz receivers at the Karl G. Jansky Very Large Array (VLA) and the 86 GHz receivers at the Atacama Large Millimeter/submillimeter Array (ALMA) to observe SiO maser lines in red giant stars. The SiO maser transitions occur at radio frequencies, where extinction is negligible, thus allowing a dense sampling of line-of-sight velocities in the most crowded regions of the Milky Way.

The overall goal of this thesis is to characterize the SiO masers in the …