  We develop a 1+1 dimensional hydrodynamical model for central heavy-ion
collisions at ultrarelativistic energies. Deviations from Bjorken's scaling are
taken into account by implementing finite-size profiles for the initial energy
density. The calculated rapidity distributions of pions, kaons and antiprotons
in central Au+Au collisions at the c.m. energy 200 AGeV are compared with
experimental data of the BRAHMS Collaboration. The sensitivity of the results
to the choice of the equation of state, the parameters of initial state and the
freeze-out conditions is investigated. Experimental constraints on the total
energy of produced particles are used to reduce the number of model parameters.
The best fits of experimental data are obtained for soft equations of state and
Gaussian-like initial profiles of the energy density. It is found that initial
energy densities required for fitting experimental data decrease with
increasing critical temperature of the phase transition.
