The NOG Sample: 3D Reconstruction of the Real-Space Density Field

We discuss the real-space reconstruction of the optical galaxy density field in the local Universe (cz < 6000 km/s) as derived from the 7076 galaxies of the Nearby Optical Galaxy (NOG) sample (see Giuricin et al. 1999 in the same volume). NOG is the currently best approximation to a homogeneous all-sky 3D optically selected galaxy sample that probes in great detail volumes of cosmological interest. Our final goal is to construct a reliable, robust and unbiased field of density contrasts over a wide range of physical scales. Exploring in detail the nature of the three dimensional galaxy distribution will provide us with invaluable qualitative cosmographical information about the topology and morphology of the local overdensities; but it also allows us to investigate on the z=0 cosmology, greatly increasing our quantitative understanding of physical parameters that constrain the evolution of structures and their clustering properties. Moreover, its near full-sky coverage and the large variety in galaxy content make the NOG ideal also for more specific tasks as the deconvolution of environmental effects from the properties and evolution history of the galaxies.