Galaxias enanas en el grupo de NGC 5044

CELLONE, S. A.

Gonnet

Congreso; 42a. Reunión Anual AAA; 1998

AAA

CCD surface photometry of a small sample of dwarf galaxies in the NGC5044 group is presented; the observations were made with the 2.15 mtelescope at CASLEO, Argentina. In particular, the use of the shape ofthe surface brightness profiles of the galaxies as a distance indicatoris addressed. This method requires that the shape of each profile bequantified by fitting it with a Sérsic model, which has a freeparameter (N) that, as has been shown, correlates with integratedmagnitude. The effects of seeing on the measured parameters of theprofiles are investigated in detail. The main conclusion of this work isthat there are relatively bright dwarf galaxies with ``convex'' profilesthat depart from the luminosity -- shape relation, preventing then itsuse as a distance indicator for individual galaxies. Alternatively,fairly reasonable distances are obtained for groups of galaxies usingthe relation between magnitude and effective surface brightness.