Involved people at OAB: Bardelli, Cappi, Origlia, Pozzetti, Zamorani, Zucca.
The Bologna Astronomical Observatory is part of the Consortium for the ESO-VLT Instrument VIRMOS (Visual Infra--Red Multi--Object Spectrograph).
The visual spectrograph will be shipped to Chile in summer 2000 and after a few months of commissioning and testing will be operational at the beginning of 2001. A couple of years later also the infrared spectrograph will be operational.
The huge multiplex capabilities of the two spectrographs will allow to
assemble redshifts of large samples of faint galaxies.
The Consortium guaranteed time will be used to perform a deep redshift
survey of more than 
galaxies selected from both visual (B and I) and
infrared (K) defined samples.
Given the large number of expected redshift measurements (about 100,000
galaxies from the shallow survey (16 sq.deg.) and about 50,000 galaxies
from the deep survey (1 sq.deg.) and the expected redshift coverage
(up to z 
2, with a median redshift
in the interval 0.6 - 0.9) this survey will allow to determine with excellent
statistics the evolution with redshift of the luminosity functions in different
bands for each galaxy type. Some of the crucial issues which will therefore
be possible to address from these data are:
a) detailed test of the predictions of various models of galaxy evolution
(e.g. hierarchical versus monolithic models);
b) precise estimate, on the basis of a single sample with well understood
selection criteria, of the star formation history up to at least z 
2;
c) study of the still uncertain nature of the extremely red galaxies (EROS),
determining which fraction of them is actually associated to old elliptical
galaxies at high redshift and which fraction is associated with dusty
starburst galaxies.
As a by-product, since no morphological selection will be applied to the
objects to be observed, this survey, with its expected 
1000 AGNs
down to I 
24.0, will allow the study of the optical luminosity
function and evolution of the faint (e.g. Seyfert-like) AGNs in a
magnitude range where the selection of the AGN candidates
with the standard color and morphological criteria is very difficult
and, possibly, largely incomplete.
This survey, which will start in 2001, has already required a lot of scientific preparation. Significant contributions were made to the following issues:
a) definition of the main scientific goals and of the observing strategy;
b) participation to the time requests to ESO for obtaining the needed photometric data in the U and K bands;
c) definition of the data management and implementation of the survey database;
d) development of software for the scientific data analysis.