Identifying Evolved Stars in the Galactic Bulge and Determining their Mass Loss

We present an update on our ongoing investigations of the relationship between evolved star mass loss and host galaxy metallicity. Our methodology involves comparisons of the mass loss rates of asymptotic giant branch (AGB) and red supergiant (RSG) stars in the Galactic bulge and the Magellanic Clouds, as inferred from modeling of AGB and RSG spectral energy distributions (SEDs). Our sample draws from the GLIMPSE surveys, but we match our sample to a number of optical and infrared surveys, including the VVV survey. After correcting for extinction, we fit each SED with models from the Grid of Red supergiant and Asymptotic giant branch ModelS (GRAMS) of dust-enshrouded evolved stars and also with a set of young stellar object (YSO) models. The best-fit model between the GRAMS and YSO models allows us to identify each source as an evolved star or a YSO. We compare our identifications of evolved stars versus YSOs to those obtained by other means. This work has been supported by NASA ADAP grant 80NSSC17K0057.