We present initial results from our ongoing program to image the Sunyaev-Zel ’ dovich ( SZ ) effect in galaxy clusters at 143 GHz using Bolocam ; five clusters and one blank field are described in this manuscript .
The images have a resolution of 58 arcsec and a radius of \simeq 6 - 7 arcmin , which is approximately r _ { 500 } -2 r _ { 500 } for these clusters .
We effectively high-pass filter our data in order to subtract noise sourced by atmospheric fluctuations , but we are able to to obtain unbiased images of the clusters by deconvolving the effects of this filter .
The beam-smoothed RMS is \simeq 10 \mu K _ { CMB } in these images ; with this sensitivity we are able to detect SZ signal to beyond r _ { 500 } in binned radial profiles .
We have fit our images to beta and Nagai models , fixing spherical symmetry or allowing for ellipticity in the plane of the sky , and we find that the best-fit parameter values are in general consistent with those obtained from other X-ray and SZ data .
Our data show no clear preference for the Nagai model or the beta model due to the limited spatial dynamic range of our images .
However , our data show a definitive preference for elliptical models over spherical models , quantified by an F -ratio of \simeq 20 for the two models .
The weighted mean ellipticity of the five clusters is \epsilon = 0.27 \pm 0.03 , consistent with results from X-ray data .
Additionally , we obtain model-independent estimates of Y _ { 500 } , the integrated SZ y -parameter over the cluster face to a radius of r _ { 500 } , with systematics-dominated uncertainties of \simeq 10 % .
Our Y _ { 500 } values , which are free from the biases associated with model-derived Y _ { 500 } values , scale with cluster mass in a way that is consistent with both self-similar predictions and expectations of a \simeq 10 % intrinsic scatter .