Cold gas properties of the Herschel Reference Survey. I. 12CO(1-0) and
  HI data
  We present new 12CO(1-0) observations of 59 late-type galaxies belonging to
the Herschel Reference Survey (HRS), a complete K-band-selected, volume-limited
(15 <D< 25 Mpc) sample of nearby galaxies spanning a wide range in
morphological type and luminosity. We studied different recipes to correct
single-beam observations of nearby galaxies of different sizes and inclinations
for aperture effects. This was done by comparing single-beam and multiple-beam
observations along the major axis, which were corrected for aperture effects
using different empirical or analytical prescriptions, to integrated maps of
several nearby galaxies, including edge-on systems observed by different
surveys. The resulting recipe is an analytical function determined by assuming
that late-type galaxies are 3D exponentially declining discs with a
characteristic scale length r_CO} = 0.2 r_24.5, where r_24.5 is the optical, g-
(or B-) band isophotal radius at the 24.5 mag arcsec^-2 (25 mag arcsec^-2), as
well as a scale height z_CO = 1/100 r_24.5. Our new CO data are then combined
with those available in the literature to produce the most updated catalogue of
CO observations for the HRS, now including 225 out of the 322 galaxies of the
complete sample. The 3D exponential disc integration is applied to all the
galaxies of the sample to measure their total CO fluxes, which are later
transformed into molecular gas masses using a constant and a
luminosity-dependent X_CO conversion factor. We also collect HI data for 315
HRS galaxies from the literature and present it in a homogenised form.
