Bibcode
DOI
Bernard, Edouard J.; Aparicio, Antonio; Gallart, Carme; Padilla-Torres, Carmen P.; Panniello, Maurizio
Bibliographical reference
The Astronomical Journal, Volume 134, Issue 3, pp. 1124-1132 (2007).
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9
2007
Citations
31
Refereed citations
29
Description
We present resolved-star VI photometry of the Local Group dwarf
irregular galaxy IC 1613 reaching I ~ 23.5, obtained with the wide-field
camera at the 2.5 m Isaac Newton Telescope. A fit to the stellar density
distribution shows an exponential profile of scale length 2.9' ±
0.1' and gives a central surface brightness μV,0 = 22.7
± 0.6. The significant number of red giant branch (RGB) stars
present in the outer part of our images (r > 16.5') indicates that
the galaxy is actually more extended than previously estimated. A
comparison of the color-magnitude diagrams (CMDs) as a function of
galactocentric distance shows a clear gradient in the age of its
population, the scale length increasing with age, while we find no
evidence of a metallicity gradient from the width of the RGB. We present
quantitative results of the recent star formation history from a
synthetic CMD analysis using IAC-STAR. We find a mean star formation
rate of (1.6 ± 0.8) × 10-3 Modot
yr-1 kpc-2 in the central r lesssim 2.5' for the
last 300 Myr.
Based on observations made with the Isaac Newton Telescope, operated on
the island of La Palma by the Isaac Newton Group, in the Spanish
Observatorio del Roque de los Muchachos of the Instituto de
Astrofísica de Canarias.