  We present ASCA temperature profiles and, when possible, crude temperature
maps for a sample of bright clusters with 0.04<z<0.09. Together with several
previously published clusters, the sample includes A85, A119, A399, A401, A478,
A644, A754, A780, A1650, A1651, A1795, A2029, A2065, A2142, A2256, A2319,
A2597, A2657, A3112, A3266, A3376, A3391, A3395, A3558, A3571, A3667, A4059,
Cygnus A, MKW3S, and Triangulum Australis. Nearly all clusters show a
significant radial temperature decline. For a typical 7 keV cluster, the
temperature decline between 1 and 6 X-ray core radii (0.15 and 0.9/h Mpc) can
be approximately quantified by a polytropic index of 1.2-1.3. Assuming such a
polytropic temperature profile, the gravitating mass within 1 and within 6 core
radii is approximately 1.35 and 0.7 times the isothermal beta-model estimates,
respectively.
  Most interestingly, we find that temperature profiles, excluding those for
the most asymmetric clusters, appear remarkably similar when plotted against
radius in units of the estimated virial radius. We compare the composite
temperature profile to the published hydrodynamic simulations. The observed
profiles appear steeper than those in most Lagrangian simulations (Evrard etal
1996; Eke etal 1997). The predictions for Omega=1 models are most discrepant,
while models with low Omega are closer to our data. We note, however, that at
least one Omega=1 Lagrangian simulation (Katz & White 1993) and the recent
high-resolution Eulerian simulation (Bryan & Norman 1997) produced clusters
with temperature profiles similar to or steeper than those observed. Our
results thus provide a new constraint for adjusting numerical simulations and,
potentially, discriminating among models of cluster formation. (ABRIDGED)
