  We present Chandra gas temperature profiles at large radii for a sample of 13
nearby, relaxed galaxy clusters and groups, which includes A133, A262, A383,
A478, A907, A1413, A1795, A1991, A2029, A2390, MKW4, RXJ1159+5531, and USGC
S152. The sample covers a range of average temperatures from 1 to 10 keV. The
clusters are selected from the archive or observed by us to have sufficient
exposures and off-center area coverage to enable accurate background
subtraction and reach the temperature accuracy of better than 20-30% at least
to r=0.4-0.5 r_180, and for the three best clusters, to 0.6-0.7 r_180. For all
clusters, we find cool gas in the cores, outside of which the temperature
reaches a peak at r =~ 0.15 r_180 and then declines to ~0.5 of its peak value
at r =~ 0.5 r_180. When the profiles are scaled by the cluster average
temperature (excluding cool cores) and the estimated virial radius, they show
large scatter at small radii, but remarkable similarity at r>0.1-0.2 r_180 for
all but one cluster (A2390). Our results are in good agreement with previous
measurements from ASCA by Markevitch et al. and from Beppo-SAX by DeGrandi &
Molendi. Four clusters have recent XMM-Newton temperature profiles, two of
which agree with our results, and we discuss reasons for disagreement for the
other two. The overall shape of temperature profiles at large radii is
reproduced in recent cosmological simulations.
