Carbon stars and C/M ratio in the WLM dwarf irregular galaxy
Abstract
We identify the rich carbon star population of the Magellanic-type dwarf irregular galaxy WLM (Wolf-Lundmark-Melotte) and study its photometric properties from deep near-IR observations. The galaxy also exhibits a clear presence of oxygen-rich population. We derive a carbon to M-star ratio of C/M = 0.56±0.12, relatively high in comparison with many galaxies. The spatial distribution of the AGB stars in WLM hints at the presence of two stellar complexes with a size of a few hundred parsecs. Using the H I map of WLM and the derived gas-to-dust ratio for this galaxy N(H I)/E(B-V) = 60±10 [ 1021 at. cm-2 mag-1] we re-determined the distance modulus of WLM from the IR photometry of four known Cepheids, obtaining (m-M)0 = 24.84±0.14 mag. In addition, we determine the scale length of 0.75±0.14 kpc of WLM disk in the J-band.
Full Table 1 is only available in electronic form at http://www.aanda.org- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 2007
- DOI:
- 10.1051/0004-6361:20054536
- arXiv:
- arXiv:astro-ph/0701727
- Bibcode:
- 2007A&A...466..501V
- Keywords:
-
- galaxies: individual: WLM;
- stars: AGB and post-AGB;
- stars: carbon;
- galaxies: irregular;
- Local Group;
- Astrophysics
- E-Print:
- 8 pages, 9 eps figures, Accepted for publication in A&