H I in nearby low-luminosity QSO host galaxies

We searched for 21 cm H I emission in a sample of 27 previously CO detected nearby galaxies hosting low-luminosity quasi-stellar objects (QSOs). In this paper we investigate the relationship between the Hi and infrared properties of these host galaxies, compare the atomic and molecular gas content and look for connections to the optical and FIR properties. The single dish observations have been made with the Effelsberg 100-m telescope with a beam size of 9.5'. The sample objects have been drawn from a wide-angle survey for optically bright QSOs (HES), which have declinations delta > -30 degrees and redshifts up to z = 0.06. 12 host galaxies from the sample have been detected in the Hi 21 cm emission line. Eight of them have a spiral geometry, whereas the other four are bulge dominated and probably of elliptical type (E/S0). Three of the objects seem to be in a phase of merging/interaction. The neutral atomic gas masses range from 1.1 x 10(9) M(circle dot) up to 3.8 x 10(10) M(circle dot). The median H I gas mass in the whole sample is of the order of 11.4 x 10(9) M(circle dot), which is a factor of two higher than the Hi content of our galaxy. We find no strong correlation between Hi mass and IR luminosity. The objects agree well within the expectations from the Tully-Fisher relation. In the color-color diagram we find all sources in the estimated locations. With the non-detected sources we clearly sample an upper envelope of this mass distribution.