The Carina Project: II. Stellar Populations
Abstract
We present a new (V,B-V) Color-Magnitude Diagram (CMD) of the Carina dwarf spheroidal (dSph) that extends from the tip of the Red Giant Branch (RGB) down to about V=25 mag. Data were collected with the Wide Field Imager (WFI) available at 2.2m ESO/MPI telescope and cover an area of about 0.3 square degrees around the center of the galaxy. We confirm the occurrence of a substantial amount of old stars with ages around 11 Gyr, together with an intermediate-age population around 5 Gyr. Moreover, we also detected a new well-defined blue plume of young Main-Sequence (MS) stars with an age at most of the order of 1 Gyr. At odds with previous results available in the literature we found thatstars along the RGB of the old and of the intermediate-age stellar populationindicate a mean metallicity roughly equal to Z=0.0004 and a small dispersion around this value. We find evidence for a smooth spatial distribution of the "intermediate-age" stellar population, which appears more centrally concentrated than the oldest one.
Keywords
Cite
@article{arxiv.astro-ph/0303493,
title = {The Carina Project: II. Stellar Populations},
author = {M. Monelli and L. Pulone and C. E. Corsi and M. Castellani and G. Bono and A. R. Walker and E. Brocato and R. Buonanno and F. Caputo and V. Castellani and M. Dall'Ora and M. Marconi and M. Nonino and V. Ripepi and H. A. Smith},
journal= {arXiv preprint arXiv:astro-ph/0303493},
year = {2009}
}
Comments
39 pages, 24 figures (PNG format). Accepted for publication on Astronomical Journal. A version with all figures included is available at http://www.mporzio.astro.it/~marco/carinaproject/