Infrared Studies of Mass Loss from Evolved Stars in the Galactic Bulge
Abstract
To investigate the relationship between mass loss from evolved stars and host galaxy metallicity, we aim to determine the total mass loss rate and average mass loss rates due to various classes of evolved stars - asymptotic giant branch (AGB) stars and red supergiant stars - in the Galactic Bulge and compare this result to that previously obtained for the Magellanic Clouds, with special attention to the dust production rates. We construct spectral energy distributions (SEDs) for our candidate RSG and AGB stars using observations from various infrared surveys, including the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). Because Robitaille et al (2008, AJ, 136, 2413) have already identified Intrinsically Red Objects from the GLIMPSE I and II surveys, we use their method as a starting point and expand the study by using the GLIMPSE 3D survey. AGB stars can be variable, so we match the GLIMPSE I, II, and 3D sources to other surveys, such as DEEP GLIMPSE, WISE, VVV, and DENIS, in order to characterize the variability across the spectral energy distribution (SED) of each source. This allows us to determine the source's average SED over multiple epochs. Then, we use extinction curves derived from Spitzer studies of extinction in the Galaxy to determine the extinction corrections for our sample. To establish dust-production rates of evolved stars in the Bulge, we use the Grid of Red supergiant and Asymptotic giant branch ModelS (GRAMS) of dust-enshrouded evolved stars (2011, A&A, 532, A54; 2011, ApJ, 728, 93). Before determining total dust return to the Bulge from these stars, we must separate and distinguish Young Stellar Objects (YSOs) from AGB stars by comparing the GRAMS fit to fits using Robitaille, et al 2017 YSO models. In the end, we present a final catalog and archive containing AGB stars found in this analysis. This work has been supported by NASA ADAP grant 80NSSC17K0057.
- Publication:
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American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23315602R