Jacobus Van Loon j.t.van.loon@keele.ac.uk
An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS). IV. Discovery of High-redshift AGB Analogs
Van Loon
Authors
Abstract
The survey for DUST in Nearby Galaxies with Spitzer (DUSTiNGS) identified several candidate Asymptotic Giant Branch (AGB) stars in nearby dwarf galaxies and showed that dust can form even in very metal-poor systems (${\boldsymbol{Z}}\sim 0.008\,{Z}_{\odot }$). Here, we present a follow-up survey with WFC3/IR on the Hubble Space Telescope (HST), using filters that are capable of distinguishing carbon-rich (C-type) stars from oxygen-rich (M-type) stars: F127M, F139M, and F153M. We include six star-forming DUSTiNGS galaxies (NGC 147, IC 10, Pegasus dIrr, Sextans B, Sextans A, and Sag DIG), all more metal-poor than the Magellanic Clouds and spanning 1 dex in metallicity. We double the number of dusty AGB stars known in these galaxies and find that most are carbon rich. We also find 26 dusty M-type stars, mostly in IC 10. Given the large dust excess and tight spatial distribution of these M-type stars, they are most likely on the upper end of the AGB mass range (stars undergoing Hot Bottom Burning). Theoretical models do not predict significant dust production in metal-poor M-type stars, but we see evidence for dust excess around M-type stars even in the most metal-poor galaxies in our sample ($12+\mathrm{log}({\rm{O}}/{\rm{H}})=7.26\mbox{--}7.50$). The low metallicities and inferred high stellar masses (up to ~10 ${M}_{\odot }$) suggest that AGB stars can produce dust very early in the evolution of galaxies (~30 Myr after they form), and may contribute significantly to the dust reservoirs seen in high-redshift galaxies.
Acceptance Date | Nov 4, 2017 |
---|---|
Publication Date | Dec 20, 2017 |
Publicly Available Date | Mar 28, 2024 |
Journal | Astrophysical Journal |
Print ISSN | 0004-637X |
Publisher | American Astronomical Society |
DOI | https://doi.org/10.3847/1538-4357/aa9892 |
Keywords | dwarf, stars, AGB and post-AGB, carbon, mass-loss, techniques, photometric |
Publisher URL | http://dx.doi.org/10.3847/1538-4357/aa9892 |
Files
Boyer_2017_ApJ_851_152.pdf
(4.4 Mb)
PDF
You might also like
Correction to: ‘A new mass-loss rate prescription for red supergiants’
(2023)
Journal Article
Downloadable Citations
About Keele Repository
Administrator e-mail: research.openaccess@keele.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search