SOFIA scientific advantages of 1-arcsecond spatial resolution in the 2 to 8 micron range

摘要

Calculations of the effect of the shear layer on image quality for a carefully designed SOFIA-type cavity show that image distortion may be less than 1 arcsec in the wavelength range beyond about 2 microns. The diameter of an image enclosing 80 of a point source reaches 1.5 arcsec at 8 microns, so the opportunity to benefit from images better than 1.5 arcsec is confined to the 2-8 micron range. This is an important range for airborne astronomy because (1) much of it is hidden from ground based observation by atmospheric absorption (primarily by H2O and CO2); (2) the reduction of background noise obtained by reducing optic temperatures to 240K is considerable in this spectral range; and (3) a great deal of important astronomical information is accessible in this wavelength range. A few examples of the scientific benefits of 1 arcsec resolution in the 2-8 micron range are briefly discussed.