We measure X-ray emission from the outskirts of the cluster of galaxies PKS0745-191 with Suzaku, determining radial profiles of density, temperature, entropy, gas fraction and mass. These measurements extend beyond the virial radius for the first time, providing new information about cluster assembly and the diffuse intracluster medium out to ~1.5r200(r200 ~= 1.7Mpc ~= 15arcmin). The temperature is found to decrease by roughly 70 per cent from 0.3 to 1r200. We also see a flattening of the entropy profile near the virial radius and consider the implications this has for the assumption of hydrostatic equilibrium when deriving mass estimates. We place these observations in the context of simulations and analytical models to develop a better understanding of non-gravitational physics in the outskirts of the cluster.
|Translated title of the contribution||X-ray observations of the galaxy cluster PKS0745-191: to the virial radius, and beyond|
|Pages (from-to)||657 - 666|
|Number of pages||10|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Publication status||Published - May 2009|