HOST GALAXIES OF THE OPTICALLY VIOLENTLY VARIABLE QUASARS PKS-0736-287 AND LB-2136(017, OJ)

Unified schemes for radio-loud active galaxies suggest that the differ ent observed classes of active galactic nuclei (AGN) arise from the sa me basic phenomenon, with the luminosity and orientation of a relativi stic jet determining the type of object seen. In the unification schem e for high-luminosity objects, optically violently variable (OVV) quas ars are those systems seen end-on (i.e. down the jet), radio quasars a re those seen at intermediate angles and Fanaroff-Riley type II (FR II ) radio galaxies are those seen edge-on. However, the past lack of det ailed information on the host galaxies of OW quasars means that it has not been possible to confirm their place within the unified scheme. I n order to provide such information, we have obtained deep optical and near-infrared images of three OVV quasars. We present both one-and tw o-dimensional numerical modelling which has been applied to derive the parameters of the underlying galaxies. We find that the host galaxy o f PKS 0736+017 is reasonably well-represented by an elliptical morphol ogy, with total absolute K-corrected galaxy magnitudes of M-V = -21.0/-0.1 and M-R = -22.0+/-0.2. Results from our two-dimensional modellin g give an observed V - R colour of 0.8+/-0.1 for the host, consistent with the underlying galaxy being elliptical. For LB 2136, the host gal axy is resolved in our near-infrared images, but the poor sampling of the frames prevents us from determining its morphological class. Assum ing an elliptical morphology we derive an absolute K-corrected magnitu de of [M-K] = -27.3+/-0.6 for the host. The situation for OJ 287 is le ss clear, with only one of our near-infrared images clearly showing th e presence of a host galaxy, from which we are unable to determine a m orphological class. From this image we derive an absolute K-corrected host galaxy magnitude of M-K = -28.9+/-0.6, assuming an elliptical mod el. Based on model tits to our optical data, we also estimate the uppe r limit on the host galaxy flux to be M-R = -22.1 (assuming an ellipti cal model). The results for PKS 0736+017 and LB 2136 are consistent wi th the proposed unification schemes, as is the estimated optical magni tude of the host in OJ 287.