Analysis and Mass Estimation of the Lensing Cluster of Galaxies CL 0024 + 17

We present a detailed analysis of Chandra X-ray observations of the lensing cluster of galaxies CL0024+17 at z = 0.395. We found that the radial temperature profile is consistent with being isothermal out to ∼ 600 kpc and that the average X-ray temperature is 4.47 −0.54 keV. The X-ray surface brightness profile is represented by the sum of extended emission centered at the central bright elliptical galaxy with a small core of 50 kpc and more extended emission which can be well described by a spherical β-model with a core radius of about 210 kpc. Assuming the X-ray emitting gas to be in hydrostatic equilibrium, we estimated the X-ray mass within the arc radius and found it is significantly smaller than the strong lensing mass by a factor of about 2–3. We detected a strong redshifted iron K line in the X-ray spectrum from the cluster for the first time and find the metal abundance to be 0.76 −0.31 solar. Subject headings: Galaxies: Clusters: Individual (CL0024+17) – X-Rays: Galaxies:– Cosmology: Gravitational Lensing – Cosmology: Dark Matter