Unbiased Correction Relations for Galaxy Cluster properties Derived from
  Chandra and XMM-Newton
  We use a sample of 62 clusters of galaxies to investigate the discrepancies
of gas temperature and total mass within r500 between XMM-Newton and Chandra
data. Comparisons of the properties show that: (1) Both the de-projected and
projected temperatures determined by Chandra are higher than those of
XMM-Newton and there is a good linear relation for the de-projected
temperature. (2) The Chandra mass is much higher than XMM-Newton mass with a
bias of 0.15. To explore the reasons for the discrepancy in mass, we
recalculate the Chandra mass (expressed as M_c) by modifying its temperature
with the de-projected temperature relation. The results show that M_c is more
close to the XMM-Newton mass with the bias reducing to 0.02. Moreover, M_c are
corrected with the r500 measured by XMM-Newton and the intrinsic scatter is
significantly improved with the value reducing from 0.20 to 0.12. These mean
that the temperature bias may be the main factor causing the mass bias. At
last, we find that M_c is consistent with the corresponding XMM-Newton mass
derived directly from our mass relation at a given Chandra mass. Thus, the
de-projected temperature and mass relations can provide unbiased corrections
for galaxy cluster properties derived from Chandra and XMM-Newton.
