Astrometric Imaging of high-redshift galaxies at 345 GHz

Recent single-dish submillimeter wavelength surveys have revolutionized observational cosmology by uncovering a substantial new population of dust-enshrouded starburst galaxies at high redshift. A tremendous amount can be learned about the star formation history of the universe by comparing the characteristics of these early sources at a range of wavelengths, from radio to X-ray. Unfortunately, the positions of these sources are not well enough determined in the parent surveys to justify devoting large amounts of time using higher-resolution instruments without first performing high-precision astrometry. The Submillimeter Array on Mauna Kea is now the ideal instrument for this, as it can observe at the same frequency as the original survey but with substaiitially better angular resolution, yielding astrometric accuracies of similar to 100 mas. We present images of the distant galaxies detected to date using the Subinillimeter Array at 345 GHz.