ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz
Jan, 2009Citations per year
Abstract: (arXiv)
The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic instrument observing at balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an {\it in situ} reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the CMB temperature. A linear model is used to compare the output of each radiometer to a set of thermometers on the instrument. Small corrections are made for the residual emission from the flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE 2 data alone show an extragalactic rise of mK at 3.3 GHz in addition to a CMB temperature of K. Combining the ARCADE 2 data with data from the literature shows a background power law spectrum of [K] from 22 MHz to 10 GHz ( GHz) in addition to a CMB temperature of K.Note:
- 11 pages 5 figures Submitted to ApJ
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