III. The dwarf spheroidal And II
Institut für Astronomie der Universität Wien, Türkenschanzstraße 17, 1180 Wien, Austria e-mail: email@example.com
2 SCFAB, Stockholm Observatory / Department of Astronomy, 10691 Stockholm, Sweden
3 Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile
Accepted: 20 July 2004
Our photometric survey of Local Group galaxies, using a four filter technique based on the method of Wing ([CITE]) allows the identification and subsequent characterization of their late-type stellar content. Two narrow band filters centred on molecular bands of TiO and CN allow us to distinguish between AGB stars of different chemistries [M-type (O-rich) and C-type (C-rich)]. The faint dwarf spheroidal galaxy And II, a member of the M 31 subgroup, was surveyed. From photometry in V and i as well as in the narrow band filters TiO and CN we were able to identify 7 new AGB carbon stars, to derive their mean absolute Mi and bolometric magnitude , their luminosity function, and their spatial distribution. We are unable to establish the true C/M ratio because the few M stars of And II are overwhelmed by foreground Galactic M stars.
Key words: stars: AGB and post-AGB / stars: carbon / galaxies: local Group / galaxies: individual: And II / techniques: photometric / surveys
Based on observations made with the Nordic Optical Telescope operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.
© ESO, 2004