  Deep XMM and Chandra observations of ClJ1226.9+3332 at z=0.89 have enabled
the most detailed X-ray mass analysis of any such high-redshift galaxy cluster.
The XMM temperature profile of the system shows no sign of central cooling,
with a hot core and a radially declining profile. A temperature map shows
asymmetry with a hot region that appears to be associated with a subclump of
galaxies at the cluster redshift, but is not visible in the X-ray surface
brightness. This is likely to be result of a merger event in the cluster, but
does not appear to significantly affect the overall temperature profile. The
XMM temperature profile, and combined Chandra and XMM emissivity profile
allowed precise measurements of the global properties of ClJ1226.9+3332; we
find kT=10.4+/-0.6keV, Z=0.16+/-0.05\Zsol, and M=5.2^{+1.0}_{-0.8}x10^{14}Msol.
We obtain profiles of the metallicity, entropy, cooling time and gas fraction,
and find a high concentration parameter for the total density profile of the
system. The global properties are compared with the local LT and MT relations,
and we are able to make the first observational test of the predicted evolution
of the YM relation. We find that departures from these scaling relations are
most likely caused by an underestimate of the total mass by ~30% in the X-ray
hydrostatic mass analysis due to the apparent recent or ongoing merger
activity.
