Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 2010 | Erratum + Published
Journal Article Open

A high-resolution VLT/FLAMES study of individual stars in the centre of the Fornax dwarf spheroidal galaxy

Abstract

For the first time we show the detailed, late-stage, chemical evolution history of a small nearby dwarf spheroidal galaxy in the Local Group. We present the results of a high-resolution (R ~ 20 000, λ = 5340–5620; 6120–6701) FLAMES/GIRAFFE abundance study at ESO/VLT of 81 photometrically selected, red giant branch stars in the central 25 of the Fornax dwarf spheroidal galaxy. We also carried out a detailed comparison of the effects of recent developments in abundance analysis (e.g., spherical models vs. plane-parallel) and the automation that is required to efficiently deal with such large data sets. We present abundances of α-elements (Mg, Si, Ca, and Ti), iron-peak elements (Fe, Ni, and Cr), and heavy elements (Y, Ba, La, Nd, and Eu). Our sample was randomly selected and is clearly dominated by the younger and more metal-rich component of Fornax, which represents the major fraction of stars in the central region. This means that the majority of our stars are 1−4 Gyr old, and thus represent the end phase of chemical evolution in this system. Our sample of stars has unusually low [α/Fe], [Ni/Fe], and [Na/Fe] compared to the Milky Way stellar populations at the same [Fe/H]. The particularly important role of stellar winds from low-metallicity AGB stars in the creation of s-process elements is clearly seen from the high [Ba/Y]. Furthermore, we present evidence of an s-process origin of Eu.

Additional Information

© 2010 ESO. Received 6 October 2009, Accepted 6 July 2010, Published online 11 November 2010. Based on FLAMES observations collected at the European Southern Observatory, proposal number 171.B-0588. Tables A1–A5 are only available in electronic form at http://www.aanda.org. This work was made possible by a grant from NWO (614.031.018). B.L. and E.T. thank Paris Observatory for hospitality and the Programme National Galaxies financial support. We thank Marco Gullieuszik and Enrico Held for sending us in advance of publication their IR photometry for stars in our sample. M.S. thanks the National Science Foundation for support under AST-0306884. E.T. gratefully acknowledges support from an NWO-VICI grant.

Attached Files

Published - Letarte2010p12365Astron_Astrophys.pdf

Erratum - aa13413e-09.pdf

Files

Letarte2010p12365Astron_Astrophys.pdf
Files (2.4 MB)
Name Size Download all
md5:d3ee888e9d52860e9ca37196dd54c11a
2.0 MB Preview Download
md5:18d71533488fb9fd4e092f7664d8cf22
396.5 kB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023