| Abstract | High sensitivity H I observations of 56 galaxies, mostly S0's (47 objects), carried out with the Arecibo radio telescope are presented. Twelve S0's and four S0/a spirals have been detected, among which 12 for the first time, and nine of them have been mapped. In addition, absorption lines have been found in two S0's. A detailed discussion of the results of the mapping has made it possible to solve several cases of confusion and to find out two possible cases of H I ring structures or flat rotation curves in S0's. Finally for six mapped galaxies, a simple deconvolution procedure has led to the derivation of the total H I fluxes and of the H I diameters; on the average, the ratio of the H I diameter to the optical one is found to be 30 percent higher for the S0's than for the spirals. |
