Preprint typeset using LATEX style emulateapj v. 5/2/11 THE VOID GALAXY SURVEY: OPTICAL PROPERTIES AND H I MORPHOLOGY AND KINEMATICS

We have carefully selected a sample of 60 galaxies that reside in the deepest underdensities of geometrically identified voids within the SDSS. H i imaging of 55 galaxies with the WSRT reveals morphological and kinematic signatures of ongoing interactions and gas accretion. We probe a total volume of 485 Mpc3 within the voids, with an angular resolution of 8 kpc at an average distance of 85 Mpc. We reach column density sensitivities of 5 × 1019 cm−2, corresponding to an H i mass limit of 3 × 108 M. We detect H i in 41 galaxies, with total masses ranging from 1.7 × 108 to 5.5 × 109 M. The upper limits on the 14 non-detections are not inconsistent with their luminosities, given their expected H i mass to light ratios. We find that the void galaxies are generally gas rich, low luminosity, blue disk galaxies, with optical and H i properties that are not unusual for their luminosity and morphology. The sample spans a range of absolute magnitudes (-16.1> Mr>-20.4) and colors (0.06 < g − r < 0.87), and includes disk and irregular galaxies. We also identify three as early type galaxies, all of which are not detected in H i. All galaxies have stellar masses less than 3 × 1010 M, and many have kinematic and morphological signs of ongoing gas accretion, suggesting that the void galaxy population is still in the process of assembling. The small scale clustering in the void, within 600 kpc and 200 km s−1, is similar to that in higher density regions, and we identify 18 H i rich neighboring galaxies in the voids. Most are within 100 kpc and 100 km s−1 of the targeted galaxy, and we find no significant population of H i rich low luminosity galaxies filling the voids, contrary to what is predicted by simulations