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We describe the development, construction, and testing of two 384 element arrays of ion-implanted semiconducting cryogenic bolometers designed for use in far-infrared and submillimeter cameras. These two dimensional arrays are assembled from a number of 32 element linear arrays of monolithic Pop-Up bolometer Detectors (PUD) developed at NASA/Goddard Space Flight Center. PUD technology allows the construction of large, high filling factor, arrays that make efficient use of available focal plane area in far-infrared and submillimeter astronomical instruments. Such arrays can be used to provide a significant increase in mapping speed over smaller arrays. A prototype array has been delivered and integrated into a ground-based camera, the Submillimeter High Angular Resolution Camera (SHARC II), a facility instrument at the Caltech Submillimeter Observatory (CSO). A second array has recently been delivered for integration into the High-resolution Airborne Widebandwidth Camera (HAWC), a far-infrared imaging camera for the Stratospheric Observatory for Infrared Astronomy (SOFIA). HAWC is scheduled for commissioning in 2005.

Measurements of the Sunyaev-Zel'dovich Effect (SZE) have long been used as probes of cosmology. The surface brightness of the SZE does not depend on redshift so blind searches for clusters, such as those currently underway with the ACT and SPT telescopes, offer an unbiased view of our Universe. However, so far observations of the SZE have been carried out at moderate to low angular resolution and our understanding of the physics of the intracluster medium (ICM) is incomplete making the interpretation of the results from such surveys difficult. For example, many calculations assume that the ICM is isothermal, yet x-ray data on nearby clusters show structure in the ICM. As its intensity falls off as density squared and distance squared, x-ray data tells us most about the cores of nearby clusters. The SZE is more sensitive to temperature variations in the ICM and to the lower-density, extended envelope of cluster plasma, thus providing a powerful and essential view to that obtained in the x-ray band. We have imaged the SZE in a preliminary sample of x-ray luminous clusters with MUSTANG, a 90 GHz, 64 pixel bolometer array on the 100-meter Green Bank Telescope (GBT). In this paper we present the highest angular resolution images of the SZE made to date. We then discuss the implications of our 8" resolution images on cluster physics.

Measurements of the Sunyaev-Zel'dovich Effect (SZE) have long been used as probes of cosmology. The surface brightness of the SZE does not depend on redshift so blind searches for clusters, such as those currently underway with the ACT and SPT telescopes, offer an unbiased view of our Universe. However, so far observations of the SZE have been carried out at moderate to low angular resolution and our understanding of the physics of the intracluster medium (ICM) is incomplete making the interpretation of the results from such surveys difficult. For example, many calculations assume that the ICM is isothermal, yet x-ray data on nearby clusters show structure in the ICM. As its intensity falls off as density squared and distance squared, x-ray data tells us most about the cores of nearby clusters. The SZE is more sensitive to temperature variations in the ICM and to the lower-density, extended envelope of cluster plasma, thus providing a powerful and essential view to that obtained in the x-ray band. We have imaged the SZE in a preliminary sample of x-ray luminous clusters with MUSTANG, a 90 GHz, 64 pixel bolometer array on the 100-meter Green Bank Telescope (GBT). In this paper we present the highest angular resolution images of the SZE made to date. We then discuss the implications of our 8" resolution images on cluster physics.