New HI 21-cm absorbers at low and intermediate redshifts
  We present the results of a survey for intervening HI 21-cm absorbers at
intermediate and low redshift (0<z<1.2). For our total sample of 24 systems, we
obtained high quality data for 17 systems, the other seven being severely
affected by radio frequency interference (RFI). Five of our targets are low
redshift (z<0.17) optical galaxies with small impact parameters (<20 kpc)
toward radio-bright background sources. Two of these were detected in 21-cm
absorption, showing narrow, high optical depth absorption profiles, the
narrowest having a velocity dispersion of only 1.5 km/s, which puts an upper
limit on the kinetic temperature of T_k<270 K. Combining our observations with
results from the literature, we measure a weak anti-correlation between impact
parameter and integral optical depth in local (z<0.5) 21-cm absorbers. Of
eleven CaII and MgII systems searched, two were detected in 21-cm absorption,
and six were affected by RFI to a level that precludes a detection. For these
two systems at z~0.6 we measure spin temperatures of T_s=(65+/-17) K and
T_s>180 K. A subset of our systems were also searched for OH absorption, but no
detections were made.
