Results of a search for faint galaxies in voids *
Received 2 May 1996 / Accepted 9 July 1996
We present the results of a search for intrinsically faint galaxies towards three regions with known voids and the Hercules supercluster. The intention was to identify galaxies of low luminosity in order to find possibly a galaxy population in the voids. Within these selected fields we increased the range of observations in comparison with the recent large field surveys which revealed the non-uniform spatial distribution of galaxies. The limiting magnitude was raised by about 5 magn., the limiting surface brightness by 2 mag/ , and the limiting diameter reduced to less than 1/3. The individual observational data of our sample are published in the previous Paper I (Hopp et al. 1995) which describes our search strategy and contains B and R magnitudes, apparent diameters, redshifts and galaxy types of about 200 newly identified objects. Their luminosity distribution demonstrates a relatively high percentage of dwarfish galaxies.
As the essential result of our survey we have to point out that no clear indication of a void-population was found. The majority of our objects lie outside voids in regions where the already known galaxies are concentrated. Some are located in the middle or near the edges of voids. They appear to be rather isolated, their distances to the nearest neighbour are quite large. Only few of our objects seem to be real void galaxies. Even in the three nearest and rather well defined voids we do not find any hitherto unknown galaxy.
Key words: large scale structure of the Universe galaxies: redshift
* Partly based on observations obtained at the European Southern Observatory, La Silla, Chile. Partly based on data-base query to the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.
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© European Southern Observatory (ESO) 1997
Online publication: July 8, 1998