  We present a study of the medium distant cluster of galaxies Abell 1835 based
on XMM-Newton data. The high quality of XMM-Newton data enable us to perform
spectro-imaging of the cluster up to large radii. We determine the gas and
total mass profiles based on the hydrostatic approach using the beta-model and
the temperature profile. For the determination of the temperature profile of
the ICM, which is needed for the mass determination, we apply a double
background subtraction, which accounts for the various kinds of background
present (particle and astrophysical background). We find a basically flat
temperature profile up to 0.75 r_200 with a temperature decrease towards the
center linked to the cooling flow. We obtain a gas mass fraction of (20.7 +/-
3.7)%, which is a lower limit on the baryon fraction in this cluster. Using
this value as baryon fraction for the entire universe, we obtain by combining
our results with results based on primordial nucleosynthesis, an upper limit
for Omega_m < 0.5h_{50}^{-1/2}, which is in good agreement with other recent
studies.
