The Abundance Spread in the Booetes I Dwarf Spheroidal Galaxy

Journal Article · Sat Dec 20 04:00:00 EST 2008 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1086/595962; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21313637

Norris, John E ^[1]; Gilmore, Gerard; Wilkinson, Mark I; Belokurov, V; Evans, N Wyn; Zucker, Daniel B ^[2]; Wyse, Rosemary F. G. , ^[3]

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1. Research School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, Cotter Road, Weston, ACT 2611 (Australia)
2. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
3. Johns Hopkins University, Department of Physics and Astronomy, 3900 North Charles Street, Baltimore, MD 21218 (United States)

We present medium-resolution spectra of 16 radial velocity red-giant members of the low-luminosity Booetes I dwarf spheroidal (dSph) galaxy that have sufficient S/N for abundance determination, based on the strength of the Ca II K line. Assuming [Ca/Fe] {approx} 0.3, the abundance range in the sample is {delta}[Fe/H] {approx} 1.7 dex, with one star having [Fe/H] = -3.4. The dispersion is {sigma}([Fe/H]) = 0.45 {+-} 0.08-similar to those of the Galaxy's more luminous dSph systems and {omega} Centauri. This suggests that the large mass ({approx}>10{sup 7} M{sub sun}) normally assumed to foster self-enrichment and the production of chemical abundance spreads was provided by the nonbaryonic material in Booetes I.

• OSTI ID: 21313637
• Journal Information: Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 2 Vol. 689; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ABUNDANCE
GALAXIES
IRON-DELTA
LUMINOSITY
MASS
RADIAL VELOCITY
SPECTRA
STARS