GEMINI - GMOS Photometry and Spectroscopy of three dwarf galaxies in the Pegasus I group

FAIFER, F.; SMITH CASTELLI, A.; GONZÁLEZ, N; NORRIS M.; ESCUDERO, C

Sao José dos Campos

Workshop; South American GEMINI Data Workshop; 2011

Oficinas Gemini Nacionales de Argentina, Brasil y Chile

The galaxy population of Pegasus has been poorly studied. Vader et al. (1994) present surface photometry for nine galaxies displaying dwarf morphologies located in the neighbourhoods of NGC 7626, but with no radial velocity information at the moment. Through a friend-of-friend algorithm, Ramella et al. (2002) identified the Pegasus I group as a physical association with 13 spectroscopically confirmed members. We present here photometric parameters, brightness and colour profiles of three early-type dwarf candidates to be members of the Pegasus I group. Through long-slit GEMINI-GMOS spectroscopy, we confirmed two of them ([VC94] 6 and [VC94] 7) as group members and we present ages and abundances determinations. Vader & Chaboyer (1994) have pointed out that [VC94] 6 displays a brightness profile similar to those of giant elliptical galaxies, therefore considering it as a likely compact elliptical (cE) galaxy. We find that this object present both photometric and spectroscopic characteristics consistent with those of cE galaxies found in other groups and clusters. However, it does not show a particularly high central surface brightness, pointing perhaps to a cE galaxy of intermediate properties.