Near - infrared imaging of the host galaxies of three radio – loud quasars at z ∼ 1 . 5

We present high spatial resolution near–infrared H-band (1.65 μm) images, taken with ISAAC on UT1 of ESO VLT, of three radio-loud quasars at z∼1.5, as a pilot study for imaging of a larger sample of radio-loud and radio-quiet quasars in the redshift range 1 < z < 2. We are able to clearly detect the host galaxy in two quasars (PKS 0000-177 and PKS 0348-120) and marginally in the third (PKS 0402-362). The host galaxies appear compact (average bulge scale-length R(e) ∼ 4 kpc) and luminous (average M(H) = –27.6±0.1). They are ∼2.5 mag more luminous than the typical galaxy luminosity (M*(H) = –25.0±0.2), and are comparable to the hosts of low redshift radio-loud quasars (M(H) ∼–26), taking into account passive stellar evolution. Their luminosities are also similar to those of high redshift radio galaxies. All three quasars have at least one close companion galaxy at a projected distance < 50 kpc from the quasar, assuming they are at the same redshift. Subject headings: Galaxies:active – Infrared:galaxies – Quasars:general