The red stellar contents of three selected fields of the local group dwarfirregular galaxy IC 1613

Citation
J. Borissova et al., The red stellar contents of three selected fields of the local group dwarfirregular galaxy IC 1613, REV MEX AST, 36(2), 2000, pp. 151-160
Citations number
28
Categorie Soggetti
Space Sciences
Journal title
REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA
ISSN journal
01851101 → ACNP
Volume
36
Issue
2
Year of publication
2000
Pages
151 - 160
Database
ISI
SICI code
0185-1101(200010)36:2<151:TRSCOT>2.0.ZU;2-8
Abstract
We present a moderately-deep JK photometry for three selected areas of the dwarf irregular galaxy IC 1613. The color-magnitude diagrams contain a mixt ure of red supergiants, asymptotic giant branch stars and the brightest red giant stars. The red supergiants are massive (20-25 M.) and young-with age s between 8 and 25 Myr. The most important result is the evidence of the de creasing density of the intermediate age AGB population in the vicinity of the HII regions in the galaxy. We also find age differences between AGB sta rs in the main body of the galaxy and those near the HII regions in the Nor th-East. The former span a range in ages between 1 and 10 Gyr, while the la tter are younger than 1 Gyr. Using the period-luminosity relation derived b y Madore & Freedman (1991) and JK magnitudes of the Cepheid variable V20, w e calculated (m - M)(K) = 24.37 +/- 0.2. The recently discovered Nova (King , Modjaz, & Li 1999) was identified in Field III. Its presence in our image s and its brightness questioned its classification as a nova.