Very metal poor Classical Cepheids: variables in IZw18
Abstract
In the framework of an ongoing ACS@HST project (HST program #10586, PI: Aloisi) we have obtained deep multi-color imaging of the very metal-poor Blue Compact Dwarf galaxy IZw18. The data were acquired in time-series fashion to allow the identification of Classical Cepheids (CCs). The main aim of this project is to constrain both the distance and the Star Formation History of the galaxy. However, as a byproduct these data also provide new insights into the properties of CCs at very low metallicities. We have identified 24 candidate CCs in IZw18. New theoretical pulsation models of CCs specifically for the low metallicity of this primordial galaxy (Z=0.0004, Y=0.24) have been computed to interpret our results.
Keywords
Cite
@article{arxiv.astro-ph/0703679,
title = {Very metal poor Classical Cepheids: variables in IZw18},
author = {G. Fiorentino and M. Marconi and G. Clementini and I. Musella and A. Aloisi and F. Annibali and R. A. Contreras and M. Tosi},
journal= {arXiv preprint arXiv:astro-ph/0703679},
year = {2009}
}
Comments
2 pages, 2 figures, Proceedings of the IAU Symp. 241 "Stellar Populations as Building Blocks of Galaxies", held in La Palma in December 2006, eds. R. F. Peletier & A. Vazdekis