Study of galaxies in the Lynx-Cancer void. I. Sample description
  The evolution of galaxies is influenced by the environment in which they
reside. This effect should be strongest for the least-mass and -luminosity
galaxies. To study dwarf galaxies in extremely low density environments we have
compiled a deep catalogue of dwarf galaxies in the nearby Lynx-Cancer void.
This void hosts some of the most metal-poor dwarfs known to date. It borders
the Local Volume at the negative supergalactic Z (SGZ) coordinates and has the
size of more than 16 Mpc. With a distance to its centre of only 18 Mpc it is
close enough to allow the search for the faintest dwarfs. Within the void 75
dwarf (-11.9 > M_B > -18.0) and 4 subluminous (-18.0 > M_B > -18.4) galaxies
have been identified. We present the parameters of the void galaxies and give a
detailed analysis of the completeness of the catalogue as a function of
magnitude and surface brightness. The catalogue appears almost complete to M_B
< -14 mag, but misses part of the fainter low surface brightness (LSB) face-on
galaxies. This sample of void galaxies builds the basis of forthcoming
observational studies that will give insight into the main stellar population,
HI-mass-to-light ratio, metallicity and age for comparison with dwarfs in
higher density regions. We briefly summarize the information on the unusual
objects in the void and conclude that their concentration hints that voids are
environments that are favourable for finding and studying unevolved dwarf
galaxies.
