Carbon- and Oxygen-rich Asymptotic Giant Branch (AGB) stars in the Bulge Asymmetries and Dynamical Evolution (BAaDE) survey

Abstract

Detections of SiO masers from the Bulge Asymmetries and Dynamical Evolution (BAaDE) survey more tightly define the region where Oxygen-rich (O) Asymptotic Giant Branch (AGB) stars reside in multiple infrared (IR) color-color diagrams. Using MSX and 2MASS data along with radio spectra from the BAaDE survey we find that three main populations were observed in the BAaDE survey: O-rich AGB stars of which about $73\%$ host SiO masers, Carbon-rich (C) AGB stars which do not host these masers, and a small contaminating set of possible Young Stellar Objects (YSOs). The distinction between YSOs and AGB stars can be drawn using only MSX data, specifically the $[D]-[E]$ color, while the shorter wavelengths provided by 2MASS are necessary to divide potential C- and O-rich AGB stars. Divisions similar to these have been seen in multiple earlier IR-studies, but BAaDE currently provides a sample of $\sim$ 15000 sources which far exceeds previous studies in sample size, and therefore provides much more distinct divisions. With these IR distinctions in place, we discuss the sources which are exceptions in either their molecular detections or IR colors, as well as the distribution of the three populations in Galactic coordinates.

accepted for publication in ApJ

References in corpus (5)

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Cited by in corpus (7)

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• AGB interlopers in YSO catalogues hunted out by NEOWISE
• Infrared color separation between thin-shelled oxygen-rich and carbon-rich AGB stars
• Volume density maps of the 862nm DIB carrier and interstellar dust: a hint for the role of carbon-rich ejecta from AGB stars?
• Ground Vibrational State SiO Emission in the VLA BAaDE Survey
• Characterizing the Evolved Stellar Population in the Galactic Foreground I: Bolometric Magnitudes, Spatial Distribution and P-L Relations
• Long-period maser-bearing Miras in the Galactic center: period-luminosity relations and extinction estimates