Emission-Line Imaging of QSOs with High Resolution

We report the first detection of emission-line gas within the host galaxies of high-redshift quasi-stellar objects (QSOs). This was done using narrowband imaging at the redshifted wavelengths of [O III] and Hα, using the PUEO adaptive optics camera of the Canada-France-Hawaii Telescope. The QSOs are all radio-quiet or very compact radio sources. In all five observed QSOs, which have redshifts 0.9 to 2.4, we find extended line emission that lies within 0.″5 (a few kiloparsecs) of the nucleus. The emission (redshifted) equivalent widths range from 35 to 300 Å. Where there is radio structure, the line emission is aligned with it. We also report on continuum fluxes and possible companions. Two of the QSOs are very red and have high resolved continuum flux.