The host galaxy of quasar IRAS 00275-2859 - an interacting system

Optical imaging of the recently discovered infrared quasar IRAS 00275-2859 (Vader and Simon 1987) shows that it can be decomposed into two point sources embedded in an underlying extended image. The brighter point source is the quasar. The authors identify the extended image together with the fainter point source as the host galaxy system. An adjacent low-surface-brightness region to the northeast is also detected in B and R. Unlike the other recently discovered IRAS quasar (13349+2438), the QSO in IRAS 00275-2859 shows a UV excess typical of optically selected quasars. The B-R rest-frame color of the host-galaxy system corresponds to that of a late-type spiral galaxy. The low-surface-brightness region to the northeast has, to within the uncertainties, the same B-R color as that of the host-galaxy system. The authors propose that the quasar belongs to one of two interacting galaxies, that the second point source is the nucleus of the second galaxy, and that the low-surface-brightness region is the tidal signature of the interaction. The infrared spectral energy distribution of IRAS 00275-2859 suggests that the bulk of the infrared radiation is emitted by heated dust in the host-galaxy system.