Translator Disclaimer
31 July 1998 Development of a broadband submillimeter grating spectrometer
Author Affiliations +
One of the central issues in astronomy is the formation and evolution of galaxies at large redshifts. Submillimeter observations are essential to understanding these processes. One of the best prospects for high redshift submillimeter observations is the study of the CII 158 micrometer fine- structure line, which carries about 0.2% of the total luminosity of nearby starburst galaxies. However, current heterodyne receivers at submillimeter observatories have insufficient bandwidth to detect the full extent of highly broadened emission lines. We are developing a broadband grating spectrometer for the Caltech Submillimeter Observatory with a total bandwidth of approximately 3400 km/s and a velocity resolution of 200 km/s. The detectors will be a linear array of 32 close-packed monolithic silicon bolometers developed at NASA's Goddard Space Flight Center. In order to achieve background-limited sensitivity, the bolometers will be cooled to 100 mK by an adiabatic demagnetization refrigerator. The spectrometer optics will consist of a tunable cryogenic immersion grating using broadband filters as order sorters. The spectrometer will be optimized to operate in the 350 micrometer and 450 micrometer atmospheric windows. Calculations of the sensitivity of the spectrometer reveal that an ultraluminous infrared galaxy of 1012 Lqq at a redshift of z equals 1 would be detectable at the 3(sigma) level in the CII line with 20 minutes of integration time.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Dominic J. Benford, Eugene Serabyn, Thomas G. Phillips, and Samuel Harvey Moseley Jr. "Development of a broadband submillimeter grating spectrometer", Proc. SPIE 3357, Advanced Technology MMW, Radio, and Terahertz Telescopes, (31 July 1998);

Back to Top