2003ApJ...588L...9M

We present optical spectroscopy of the host galaxies of four quasi-stellar objects (QSOs)–PG 1444+407, PKS 2349-147, 3C 323.1, and 4C 31.63–having a redshift range 0.1≤z≤0.3. The spectra were obtained at the Keck Observatory with the Low Resolution Imaging Spectrograph instrument offset 2"-4" from the nucleus at several position angles in each galaxy. The objects close to 3C 323.1 and PKS 2349-147 have the same redshifts as their nearby QSOs and appear to be the nuclei of galaxies in the final states of merging with the host galaxies. The spectra of the hosts show some variety: PKS 2349-147 and 3C 323.1 show strong off-nuclear emission lines plus stellar absorption features, while the other two show only stellar absorption. PKS 2349-147 and PG 1444+407 have a mixture of old and moderately young stars, while 4C 31.63 has the spectrum of a normal giant elliptical galaxy, which is very rare in our larger sample. The spectrum of the host of 3C 323.1 appears to be dominated by older stars, although our data for it are of lower quality. The redshifts of the off-nucleus emission lines and stellar components are very close to those of the associated QSOs.