``The Sunyaev-Zel'dovich Effect Spectrum in Abell 2163''

Manuscript: Postscript


We present a measurement of the Sunyaev-Zel'dovich effect (SZE) at 30 GHz for the galaxy cluster Abell 2163. Combining this data point with previous measurements at 140, 220, and 270 GHz from the SuZIE and Diabolo experiments, we construct the most complete SZE spectrum to date. The spectrum is fitted to determine the Compton y-parameter (y_o) and the peculiar velocity (v_p) for this cluster. Our results are y_o=3.60^{+0.39}_{-0.39}^{+0.36}_{-0.29}x10^{-4} and v_ p=360^{+780}_{-650}^{+350}_{-330} km/s where the uncertainties correspond to statistical followed by systematic at 68% confidence. These results include corrections for contamination by Galactic dust emission; we find the contamination level to be much less than previously reported. The dust emission, while strong, is distributed over much larger angular scales than the cluster signal and contributes little to the measured signal when the proper SZE observing strategy is taken into account.