Studies of narrow polar rings around E galaxies. II. The UV spectrum of AM 2020-504.
Buson, Lucio; Arnaboldi, Magda; Longo, Giuseppe; Capaccioli, Massimo; Barbaro, Guido
Italy
Abstract
Four ultraviolet (UV) full-shift spectra secured with the IUE satellite have been used to test the accretion scenario for the still unexplored class of the "narrow" polar ring (PR) galaxies. The UV energy distribution in the λλ 1200 - 3300 A range for the "prototype" of this class, the system AM 2020-504, is found to be different from the UV emission of a standard E galaxy and to show evidence for a burst of star formation. A model of a star burst occurring in an elliptical galaxy is proposed to account for the spectral energy distribution and the observed colors; we find a lower limit of 1.5 x 10^8^ yr to the age of the PR in AM 2020-504 and we estimate that the mass involved in the starburst is 4 x 10^8^M_sun_.