Near-Infrared Imaging of Steep Spectrum Radio Quasars

Abstract

We present near-infrared imaging of 19 steep spectrum radio quasars (SSRQ) at 0.5 < z < 1. This sample is matched in redshift and optical and radio luminosity with our previously studied sample of 20 flat spectrum radio quasars (FSRQ). The host galaxy is clearly detected in 10, marginally in 6, and remains unresolved in 3 SSRQs. The SSRQ host galaxies are ~2 mag. brighter than L* galaxies, and ~1 mag. brighter than brightest cluster galaxies. The SSRQ hosts have similar luminosity to FSRQ hosts, and fall between the luminosities of lower and higher redshift radio-loud quasars. The nucleus-to-galaxy luminosity ratio of SSRQs is much smaller than that of FSRQs. We confirm for the most luminous SSRQs the trend noted for the FSRQs of a minimum host galaxy luminosity which increases linearly with the nuclear luminosity. Finally, FSRQs seem to reside in richer environments than SSRQs, as evidenced by a larger number of close companion galaxies.