The Interferometric Sunyaev-Zel'dovich Effect Imaging
team has successfully observed 27 intermediate
redshift and distant galaxy clusters by retrofitting the BIMA and OVRO
mm-wave arrays with low-noise HEMT receivers operating from 26 -
36 GHz. These observations have led to high
quality images; in addition, these observations are being used to make
SZE estimates of cluster gas masses and gas mass
fractions and to measure direct cluster distances by combining SZE and X-ray
imaging and spectroscopic observations.
Because of the redshift independence of the SZE cluster
decrement, a dedicated SZE imaging
array would make an ideal instrument for surveying the high redshift
universe for massive, collapsed structures.
Although the sensitive 30 GHz receivers coupled to the BIMA and OVRO arrays have
provided the high signal to noise constraints on the gas distribution of
the highest redshift clusters, the SZE Imaging Experiment in its current
form is not sufficiently sensitive to carry out a meaningful high redshift
cluster survey. Therefore, we are now building a new array optimized
for high redshift cluster detection, the Sunyaev-Zel'dovich
The SZA consists of eight 3.5 m dishes and a digital
correlator with 8 GHz bandwidth. It will have low-noise HEMT
operating at 26 - 36 GHz and also at 85 - 115 GHz.
It will survey approximately 100 times
faster than the current fastest SZE imaging system on BIMA, and it will
allow us to probe the distant universe for galaxy clusters.
The SZA will be operated with the existing six 10.4 m OVRO
telecopes to form a novel, powerful, heteorgeneous array. This
initially used for identifying and removing point source
from the SZE survey. It will also allow unprecedented imaging of
the SZE for distant clusters.
The SZA is funded by a direct grant from the
The National Science Foundation
with enhancement from 6 to 8 antenna (doubling the number of
baselines), and 90 GHz capability made possible by a contribution
Center for Cosmological Physics.
A document describing specific digital correlator configurations
for the proposed array in