Arcmin Field Of View Research Articles

Design Of A Wide Field Of View Phased Array Telescope

The design of the Multipurpose Multiple Telescope Testbed (MMTT) is described. The MMTT, whose construction is now nearly complete, is believed to be the first wide field of view phased array imaging telescope. The design philosophy and alignment requirements are discussed and the telescope is described. The array consists of four 20 cm telescopes and operates with visible light. The coherently combined image has a 30 arcmin field of view. A key design goal is the maintenance of lateral pupil geometry to within 1µm of the ideal. Two mirrors behind each afocal telescope combine the four beams into one and are actuated to control both tilt and piston. Together, the two beam combiner mirrors control lateral pupil geometry. A control system senses the lateral pupil geometry error by continuously measuring piston phase changes over the telescope field of view. A discrete time varying Kalman filter then processes these measurements to estimate lateral pupil geometry errors.

Evolution of Very Faint Field Galaxies and Quasars

This paper reports preliminary results of two long-term redshift surveys that are near completion. One consists of nearly 400 redshifts of field galaxies; the sample is faint enough (B ≲ 22) to test models of galaxy luminosity and color evolution (and possibly cosmology) and to search for the presence of very large-scale structures among distant field galaxies. The other consists of over 60 spectra of quasar candidates of similar faintness; the identifications and redshifts of bona-fide quasars provide strong constraints on the evolution and shape of the luminosity function of distant quasars. Almost all of the observations have been made with the 4m telescope at Kitt Peak National Observatory with the Cryogenic Camera in multiaperture mode. The spectral range covered 4500Å to 7500Å with 15Å FWHM resolution and 4Å per pixel; simultaneous exposures of an hour or two were made for about 10 objects within the 5 arcmin field of view.

Low Energy X-ray Map of Puppis A Supernova Remnant

THE low energy X-ray emission from the Puppis A supernova remnant has recently been observed with the Mullard Space Science Laboratory grazing incidence telescopes on Copernicus. The instrumentation has been described before1. The observations reported here are from the 0.5–1.5 keV detector system. The whole of the radio remnant has been mapped using the 10 arc min field of view. Some additional data from the 6 arc min field of view are also presented.