An Hi survey of the Bo otes void . II . The

We discuss the results of a VLA 1 (Napier et al. 1983) Hi survey of the Boo otes void and compare the distribution and Hi properties of the void galaxies to those of galaxies found in a survey of regions of mean cosmic density. The Boo otes survey covers 1100 Mpc 3 , or 1% of the volume of the void and consists of 24 cubes of typically 2 Mpc 2 Mpc 1280 km s ?1 , centered on optically known galaxies. Sixteen targets were detected in Hi; 18 previously uncataloged objects were discovered directly in Hi. The control sample consists of 12 cubes centered on IRAS selected galaxies with FIR luminosities similar to those of the Boo otes targets and located in regions of 1 to 2 times the cosmic mean density. In addition to the 12 targets 29 companions were detected in Hi. We nd that the number of galaxies within 1 Mpc of the targets is the same to within a factor of two for void and control samples, and thus that the small scale clustering of galaxies is the same in regions that diier by a factor of 6 in density on larger scales. A dynamical analysis of the galaxies in the void suggests that on scales of a few Mpc the galaxies are gravi-tationally bound, forming interacting galaxy pairs, loose pairs and loose groups. One group is compact enough to qualify as a Hickson compact group (hereafter HCG) (Hickson 1982). The galaxies found in the void are mostly late-type, gas rich systems. A careful scrutiny of their Hi and optical properties shows them to be very similar to eld galaxies of the same morphological type. This, combined with our nding that the small scale clustering of the galaxies in the void is the same as in the eld, suggests that it is the near environment that mostly aaects the evolution of galaxies.