Carbon Star Survey in the Local Group. VI. The Dwarf Spheroidal Galaxy NGC 205
Abstract
We present a CFH12K survey of the carbon stars in NGC 205 and its surrounding field. We find that the number of C stars in NGC 205 is low (~500) for its luminosity and that very few C stars are seen outside of the 10' isophote, suggesting tidal stripping by M31. Their <MI>=-4.54, a magnitude nearly identical to what has been found in other galaxies with numerous C stars. Stars with accurate (R-I) photometry, to I~22.5, are used to determine the outer profile of NGC 205. A King profile with rt=19.77‧+/-3.00‧ fits the data for distances larger than 7'. This rt implies that NGC 205 reached a minimum distance to M31 of ~42 kpc. The spatial distribution of C stars in the surrounding field reveals that some C stars belong to to the disk of M31, seen in projection, and that a surplus of C stars seen west of NGC 205 could be part of tidal debris left along its orbit. Finally, we report evidence of a transient period of enhanced star formation that occurred 1-2 Gyr ago in the northwest half of NGC 205.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 2003
- DOI:
- 10.1086/375309
- Bibcode:
- 2003AJ....125.3037D
- Keywords:
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- Galaxies: Individual: NGC Number: NGC 205;
- Galaxies: Stellar Content;
- Galaxies: Structure;
- Stars: Carbon