XMM-Newton study of the lensing cluster of galaxies CL0024+17
  We present a detailed gravitational mass measurement based on the XMM-Newton imaging spectroscopy analysis of the lensing cluster of galaxies CL0024+17 at z=0.395. The emission appears approximately symmetric. However, on the scale of r~3.3' some indication of elongation is visible in the northwest-southeast (NW-SE) direction from the hardness ratio map (HRM). Within 3', we measure a global gas temperature of 3.52\pm0.17 keV, metallicity of 0.22\pm0.07, and bolometric luminosity of 2.9\pm0.1 \times 10^{44} h^{-2}_{70} erg/s. We derive a temperature distribution with an isothermal temperature of 3.9 keV to a radius of 1.5' and a temperature gradient in the outskirts (1.3<r<3'). Under the assumption of hydrostatic equilibrium, we measure gravitational mass and gas mass fraction to be M_{200}=2.0\pm0.3 \times 10^{14} h_{70}^{-1} M_{\odot} and f_{\rm gas}=0.20\pm0.03 h^{-3/2}_{70} at r_{200}=1.05 h^{-1}_{70} Mpc using the observed temperature profile. The complex structure in the core region is the key to explaining the discrepancy in gravitational mass determined from XMM-Newton X-ray observations and HST optical lensing measurements. 
Y.-Y. Zhang, H. Boehringer, Y. Mellier, G. Soucail, W. Forman