A New Class of Massive Spiral Galaxies with High HI Masses

The most extensive HI survey, obtained with Arecibo, revealed a new category ofspiral galaxy in the local volume: massive spirals with a gaseous contentcomparable the stellar mass. These galaxies have high spin parameters, which maybe slowing the conversion of gas into stars. The gaseous disks are regular,suggesting that they arise from a radiatively cooling hot galactic halo that isparticularly massive and Xray luminous. These may be local analogs to theactive hot mode accretion process that was common at z virgul 13 but is rare today.We propose the first Xray observations of this newly recognized class ofgalaxies. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]