Chandra observations of the galaxy cluster Abell 1835

We present the analysis of 30 ksec of Chandra observations of the galaxy cluster Abell 1835. Overall, the X-ray image shows a relaxed morphology, although we detect substructure in in the inner 30 kpc radius. Spectral analysis shows a steep drop in the X-ray gas temperature from ∼12 keV in the outer regions of the cluster to ∼4 keV in the core. The Chandra data provide tight constraints on the gravitational potential of the cluster which can be parameterized by a Navarro, Frenk & White (1997) model. The X-ray data allow us to measure the X-ray gas mass fraction as a function of radius, leading to a determination of the cosmic matter density of Ωm = 0.40±0.09 h −0.5 50 . The projected mass within a radius of ∼150kpc implied by the presence of gravitationally lensed arcs in the cluster is in good agreement with the mass models preferred by the Chandra data. We find a radiative cooling time of the X-ray gas in the centre of Abell 1835 of about 3×10 yr. Cooling flow model fits to the Chandra spectrum and a deprojection analysis of the Chandra image both indicate the presence of a young cooling flow (∼ 6×10 yr) with an integrated mass deposition rate of 230 −50 M⊙ yr −1 within a radius of 30 kpc. We discuss the implications of our results in the light of recent RGS observations of Abell 1835 with XMM-Newton.