The temperature and distribution of gas in CL 0016+16 measured with XMM-Newton

We present the results of a 37-ks observation of CL 0016+16 with the XMM-Newton EPIC instrument. Within 1.5 arcmin of the cluster centre we measured a gas temperature of kT= 9.13^+0.24_-0.22 keV and an abundance of 0.22^+0.04_-0.03 times the solar value (1σ uncertainties). This significant improvement over previous measurements has allowed us to revise the estimate of the Hubble constant based on CL 0016+16 to 68 +/- 8 km s^-1 Mpc^-1 (random error only), close to the value from the Hubble Space Telescope distance-scale project. The total gravitating mass within a radius of 248 kpc of the cluster centre is in good agreement with that found from gravitational lensing over the same region, supporting the assumption of isothermal gas in hydrostatic equilibrium. The gas mass fraction of 0.13 +/- 0.02 is in remarkable agreement with that given by cosmological parameters for the Universe as a whole, suggesting that CL 0016+16 is a fair sample of the matter content of the Universe. While there is no spectral or spatial evidence to suggest a cooling flow in CL 0016+16, we find an asymmetrical central X-ray structure which may have a harder spectrum than the cluster as a whole, and be evidence for some merger activity, in addition to a previously reported asymmetry to the west of the cluster. The nearest companion cluster to CL 0016+16 is measured to have a gas temperature of kT= 3.8^+0.3_-0.3 keV and an abundance of 0.6^+0.3_-0.2 times the solar value (1σ uncertainties). We also present spectral data for the companion quasar whose spectrum was confused with CL 0016+16 in previous ASCA data.