5 Conclusion

In this paper we presented an HI search for 257 candidates for nearby dwarf galaxies. A detection rate of 60% on the average is quite high keeping in mind the limited velocity band and the fact that single-dish telescopes are literally "blind'' for weak emission in the velocity range of the local HI emission (i.e. within -140 to +20 kms^-1) and for 20% of HI-poor (spheroidal and Sph/Ir) objects in the sample. Most of the detected galaxies are located within the local supercluster, and about 25% are members of the Local Volume. The dwarfs within the Local Volume have a mean linear diameter of $1.4 \pm 0.2$ kpc, a mean observed linewidths of 39 kms^-1, and a mean total HI mass of 4.6 10⁷ $M_{\odot}$. The smallest galaxies have HI masses of just over 10⁶ solar masses. Once this full-sky survey will be finished we will be able to discuss the luminosity function of the Local Volume including these tiny dwarf galaxies. This investigation is especially needed as recent determinations of the galaxy luminosity function exhibit an increase for low mass objects. The exact value of this increase will be important for deriving the mass density in the local universe.

Acknowledgements

The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

The Nançay Radio Astronomy Observatory is the Unité Scientifique de Nançay of the Observatoire de Paris, associated as Unité de Service et de Recherche (USR) No. B704 to the French Centre National de la Recherche Scientifique (CNRS). The Observatory also gratefully acknowledges the financial support of the Conseil Régional of the Région Centre in France.

This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

This work has been partially supported by the Deutsche Forschungsgemeinschaft (DFG) under project No. 436 RUS 113/470/0 and Eh 154/1-1.