Title | X-ray observations of Abell 2218 and implications for the Sunyaev-Zel'dovich effect. |
Authors | Boynton, P. E.; Radford, S. J. E.; Schommer, R. A.; Murray, S. S. |
Bibcode | 1982ApJ...257..473B Search ADS ↗ |
Abstract | The Einstein Observatory was used to obtain a high-resolution X-ray image and an X-ray flux measurement of the galaxy cluster Abell 2218. The combined system of intracluster medium and galaxies is modeled as a gas in hydrostatic equilibrium in a common gravitational potential with an isothermal galaxy component. This model is then fitted in the least-squares sense to the X-ray surface brightness distribution and to the optically determined galaxy surface density profile to determine model parameters. The gas is found to be nominally isothermal, moderately dense, and very hot (10-30 keV); these conditions are consistent with the Sunyaev-Zel'dovich effect, i.e., the diminution in the cosmic microwave background radiation intensity in the direction of this cluster. It is noted that the considerable imprecision inherent in the method of distance measurement based on the combination of microwave measurements with X-ray and optical data makes it impossible to make a definitive statement about the distance to Abell 2218. |
Objects | 8 Objects Search NED ↙ |