This grant will enable the addition of three new millimeter wave antennas to the BIMA array, bringing the total number of antennas from six to nine. The increase to nine will provide substantial increases in speed and sensitivity, permitting a much greater range of scientific problems to be addressed by BIMA scientists and visitors. A single day's observing will yield maps with as many as 800 independent pixels. The speed is essential for studying time varying phenomena, such as comets, solar flares, and interstellar masers. The added sensitivity will allow, for example, molecular line mapping in distant galaxies. The initial array configuration will allow observations at 70-90 GHz, 90-116 GHz, and 210-270 GHz with an IF bandwidth of 830 MHz and a spectral line correlator that covers 800 MHz, nearly the whole IF band. The system will have excellent sensitivity for both line and continuum, with an effective sensitivity that is comparable to the major single millimeter antennas in the world. The schedule for construction will bring the full nine element array into operation in the spring of 1992.
