DUST in Nearby Galaxies with Spitzer (DUSTiNGS): An Infrared Census of Extreme AGB Stars in Nearby Dwarf Galaxies
Abstract
Nearby resolved dwarf galaxies provide excellent opportunities for studying the dust-producing late stages of stellar evolution. DUSTiNGS (DUST in Nearby Galaxies with Spitzer) is a 3.6- and 4.5-μm imaging survey of 50 dwarf galaxies within 1.5 Mpc. We obtained observations in two epochs, separated by approximately 6 months, to assist in identifying long-period thermally-pulsing (TP-)AGB stars. We find more than 500 dusty variable TP-AGB stars (sometimes called extreme AGB stars). The majority of these stars are new discoveries, including 12 with [Fe/H]<-2 dex. These stars are likely in the superwind phase and thus dominate the current AGB dust input to the interstellar medium of their respective galaxies.
- Publication:
-
Why Galaxies Care about AGB Stars III: A Closer Look in Space and Time
- Pub Date:
- August 2015
- Bibcode:
- 2015ASPC..497..453B