English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The survey for DUST in Nearby Galaxies with Spitzer (DUSTiNGS) identifiedseveral candidate Asymptotic Giant Branch (AGB) stars in nearby dwarf galaxiesand showed that dust can form even in very metal-poor systems (Z ~ 0.008$Z_\odot$). Here, we present a follow-up survey with WFC3/IR on the HubbleSpace Telescope (HST), using filters that are capable of distinguishingcarbon-rich (C-type) stars from oxygen-rich (M-type) stars: F127M, F139M, andF153M. We include six star-forming DUSTiNGS galaxies (NGC 147, IC 10, PegasusdIrr, Sextans B, Sextans A, and Sag DIG), all more metal-poor than theMagellanic Clouds and spanning 1 dex in metallicity. We double the number ofdusty AGB stars known in these galaxies and find that most are carbon rich. Wealso find 26 dusty M-type stars, mostly in IC 10. Given the large dust excessand tight spatial distribution of these M-type stars, they are most likely onthe upper end of the AGB mass range (stars undergoing Hot Bottom Burning).Theoretical models do not predict significant dust production in metal-poorM-type stars, but we see evidence for dust excess around M-type stars even inthe most metal-poor galaxies in our sample (12+log(O/H) = 7.26-7.50). The lowmetallicities and inferred high stellar masses (up to ~10 $M_\odot$) suggestthat AGB stars can produce dust very early in the evolution of galaxies (~30Myr after they form), and may contribute significantly to the dust reservoirsseen in high-redshift galaxies.

An Infrared Census of DUST in Nearby Galaxies with Spitzer (DUSTiNGS). IV. Discovery of High-Redshift AGB Analogs