A census of AGB stars in Local Group galaxies ^*,**

III. The dwarf spheroidal And II

¹ Institut für Astronomie der Universität Wien, Türkenschanzstraße 17, 1180 Wien, Austria e-mail: kerschbaum@astro.univie.ac.at
² SCFAB, Stockholm Observatory / Department of Astronomy, 10691 Stockholm, Sweden
³ Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile

Received: 6 April 2004
Accepted: 20 July 2004

Abstract

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 M_i 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.