Carbon star survey of Local Group galaxies. X. Wolf-Lundmark-Melotte a galaxy with an extreme C/M ratio
Abstract
We used the CFH12K wide field camera to survey the carbon star population of the Wolf-Lundmark-Melotte system using the CN-TiO technique. 149 C stars are identified with a mean < I > = 20.28, corresponding to < MI> = -4.65, a mean luminosity similar to what we found in other irregular galaxies. Star counts in and around the main body of WLM reveal that its stellar distribution is quite elliptical (ɛ = 0.58) with major and minor axes of 26' and 11'. Comparison of the density profile of C stars and old red giants shows that their scale lengths differ by only 15% pointing to mixed populations. WLM is found to be unique among dwarf irregular galaxies by having essentially a handful of early-type AGB M stars thus leading to an extreme C/M ratio. We conclude that like NGC 3109, WLM is a disk shaped galaxy, seen at an inclination of ∼ 69o and devoid of an extended spherical stellar halo.
Based on observations carried out at the Canada-France-Hawaii Telescope, operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique de France, and the University of Hawaii. Full Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/416/111- Publication:
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Astronomy and Astrophysics
- Pub Date:
- March 2004
- DOI:
- 10.1051/0004-6361:20034557
- Bibcode:
- 2004A&A...416..111B
- Keywords:
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- galaxies: individual: Wolf-Lundmark-Melotte