Databases from Cosmic Background Explorer (COBE)

Abstract

The Cosmic Background Explorer (COBE)¹ was launched in November 1989. Its scientific objectives are to search for spatial anisotropics and spectral distortions in the 2.7 K cosmic microwave background (CMB) radiation, to detect the diffuse infrared background radiation from the first objects to form after the Big Bang, and to study all other sources of diffuse radiation from 1 micron to 1 centimeter. These other sources include interplanetary and interstellar dust, hot electrons in the Galaxy, faint stars in the Galaxy, and possibly IR galaxies and hot gas in galaxy clusters. To map these primeval and local sources, the three scientific instruments on COBE scan the sky repeatedly, building up signal-to-noise statistics until the data are limited only by the astrophysical environment. The three instruments are the DIRBE (Diffuse Infrared Background Experiment) covering 1 to 300 micron with a 10 band filter photometer and a 0.7° beamwidth; the FIRAS (Far Infrared Absolute Spectrophotometer) covering 100 microns to 1 cm with an absolutely calibrated polarizing Michelson interferometer with a 5 percent spectral resolution and a 7° beamwidth; and the DMR (Differential Microwave Radiometers) covering 31.5,53, and 90 GHz with 7° beamwidth. COBE is described further elsewhere (see Gulkis et al., 1990).