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Ground-based & WFPC2 Imaging of Fornax: Spatial Variations in Star Formation History

Published online by Cambridge University Press:  25 May 2016

Eva K. Grebel
Affiliation:
UCO/Lick Obs., University of California, Santa Cruz, CA 95064, USA
Peter B. Stetson
Affiliation:
National Research Council, Herzberg Institute of Astrophysics, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria, British Columbia, V8X 4M6, Canada

Abstract

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Fornax shows a radial age gradient. The old population is the most extended one similar to what was found in other dwarf galaxies, while younger populations are more centrally concentrated. With ≈ −1.2 dex the dominant intermediate-age population is much more metal-rich than the oldest populations traced by Fornax's globular clusters (≈ −2 dex, 15–11 Gyr). Star formation appears to have proceeded continuously with decreasing rates rather than in distinct episodes. Fornax contains the youngest population ever found in a dwarf spheroidal galaxy, 100–200 Myr, which makes its apparent lack of gas even more puzzling.

Type
Part 2: The Database
Copyright
Copyright © Astronomical Society of the Pacific 1999 

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