Low-frequency measurements of the CMB (cosmic microwave background) spectrum

• Main Authors: Kogut, A., Bensadoun, M., De Amici, G., Levin, S., Limon, M., Smoot, G. ), Sironi, G. . Dipt. di Fisica), Bersanelli, M., Bonelli, G. )
• Language: unknown
• Published: 2008
• Subjects: 71 CLASSICAL AND QUANTUM MECHANICS; GENERAL PHYSICS; 47 OTHER INSTRUMENTATION; COSMIC RADIATION; MEASURING METHODS; BACKGROUND RADIATION; FREQUENCY DEPENDENCE; MICROWAVE RADIATION; SPECTRA; TEMPERATURE DEPENDENCE; ELECTROMAGNETIC RADIATION; IONIZING RADIATIONS; RADIATIONS; South Pole; South pole
• Online Access: http://www.osti.gov/servlets/purl/6830781; https://www.osti.gov/biblio/6830781

As part of an extended program to characterize the spectrum of the cosmic microwave background (CMB) at low frequencies, we have performed multiple measurements from a high-altitude site in California. On average, these measurements suggest a CMB temperature slightly lower than measurements at higher frequencies. Atmospheric conditions and the encroachment of civilization are now significant limitations from our present observing site. In November 1989, we will make new measurements from the South Pole Amnudsen-Scott Station at frequencies 0.82 1.5, 2.5, 3.8, 7.5, and 90 GHz. We discuss recent measurements and indicate improvements from a polar observing site. 11 refs., 2 figs.