The ACS LCID Project: RR Lyrae Stars as Tracers of Old Population Gradients in the Isolated Dwarf Spheroidal Galaxy Tucana

We present a study of the radial distribution of RR Lyrae variables, which present a range of photometric and pulsational properties, in the dwarf spheroidal galaxy Tucana. We find that the fainter RR Lyrae stars, having a shorter period, are more centrally concentrated than the more luminous, longe...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2008-05, Vol.678 (1), p.L21-L24
Main Authors: Bernard, Edouard J, Gallart, Carme, Monelli, Matteo, Aparicio, Antonio, Cassisi, Santi, Skillman, Evan D, Stetson, Peter B, Cole, Andrew A, Drozdovsky, Igor, Hidalgo, Sebastian L, Mateo, Mario, Tolstoy, Eline
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present a study of the radial distribution of RR Lyrae variables, which present a range of photometric and pulsational properties, in the dwarf spheroidal galaxy Tucana. We find that the fainter RR Lyrae stars, having a shorter period, are more centrally concentrated than the more luminous, longer period RR Lyrae variables. Through comparison with the predictions of theoretical models of stellar evolution and stellar pulsation, we interpret the fainter RR Lyrae stars as a more metal-rich subsample. In addition, we show that they must be older than about 10 Gyr. Therefore, the metallicity gradient must have appeared very early on in the history of this galaxy.
ISSN:1538-4357
0004-637X
1538-4357
DOI:10.1086/588285