G. Kauffmann et S. Charlot, CONSTRAINTS ON MODELS OF GALAXY FORMATION FROM THE EVOLUTION OF DAMPED LYMAN-ALPHA ABSORPTION SYSTEMS, The Astrophysical journal, 430(2), 1994, pp. 120000097-120000100
There is accumulating observational evidence suggesting that damped Ly
alpha absorption systems are the progenitors of present-day spiral gal
axies. We use the observed properties of these systems to place constr
aints on the history of star formation in galactic disks, and on cosmo
logical theories of structure formation in the universe. We show that
the observed increase in OMEGA(HI) Contributed by damped Lyalpha syste
ms at high redshift implies that star formation must have been conside
rably less efficient in the past. We construct a model in which gas is
converted into stars with an efficiency that increases with time, and
we show that this model can reproduce most of the observed properties
of damped Lyalpha systems, including the observed distribution of col
umn densities. We also show that the data can constrain cosmological m
odels in which structure forms at late epochs. A mixed dark matter (MD
M) model with OMEGA(nu) = 0.3 is unable to reproduce the mass densitie
s of cold gas seen at high redshift, even in the absence of any star f
ormation. We show that at redshifts greater than 3, this model predict
s that the total baryonic mass contained in dark matter halos with cir
cular velocities V(c) > 35 km s-1 is less than the observed mass of H
I in damped systems. At these redshifts, the photoionizing background
would prevent gas from dissipating and collapsing to form high column
density systems in halos smaller than 35 km s-1.