Journal
ASTROPHYSICAL JOURNAL
Volume 716, Issue 1, Pages 446-452Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/716/1/446
Keywords
galaxies: dwarf; galaxies: individual (Leo IV); Local Group; stars: abundances
Categories
Funding
- Carnegie Institution of Washington
- NASA [HST-HF-01233.01, NAS 5-26555]
Ask authors/readers for more resources
We present high-resolution Magellan/MIKE spectroscopy of the brightest star in the ultra-faint dwarf galaxy Leo IV. We measure an iron abundance of [Fe/H] = -3.2, adding to the rapidly growing sample of extremely metal-poor (EMP) stars being identified in Milky Way satellite galaxies. The star is enhanced in the a elements Mg, Ca, and Ti by similar to 0.3 dex, very similar to the typical Milky Way halo abundance pattern. All of the light and iron-peak elements follow the trends established by EMP halo stars, but the neutron-capture elements Ba and Sr are significantly underabundant. These results are quite similar to those found for stars in the ultra-faint dwarfs Ursa Major II, Coma Berenices, Bootes I, and Hercules, suggesting that the chemical evolution of the lowest-luminosity galaxies may be universal. The abundance pattern we observe is consistent with predictions for nucleosynthesis from a Population III supernova explosion. The extremely low metallicity of this star also supports the idea that a significant fraction (similar to 10%) of the stars in the faintest dwarfs have metallicities below [Fe/H] = -3.0.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available