  We study the response of an infinite system of point particles on the line
initially at rest on the instantaneous release of energy in a localized region.
We make a detailed comparison of the hydrodynamic variables predicted by Euler
equations for non-dissipative ideal compressible gas and the results of direct
microscopic simulations. At long times the profiles of the three conserved
variables evolve to self-similar scaling forms, with a scaling exponent as
predicted by the Taylor-von Neumann-Sedov (TvNS) blast-wave solution. The
scaling functions obtained from the microscopic dynamics show a remarkable
agreement with the TvNS predictions, except at the blast core, where the TvNS
solution predicts a diverging temperature which is not observed in simulations.
We show that the effect of heat conduction becomes important and present
results from a numerical solution of the full Navier-Stokes-Fourier equations.
A different scaling form is observed in the blast core and this is carefully
analyzed. Our microscopic model is the one-dimensional alternate mass
hard-particle gas which has the ideal gas equation of state but is
non-integrable and known to display fast equilibration.
