ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The ARCADE 2 instrument has measured the absolute temperature of the sky atfrequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenicinstrument observing at balloon altitudes with no emissive windows between thebeam-forming optics and the sky. An external blackbody calibrator provides an{\it in situ} reference. Systematic errors were greatly reduced by usingdifferential radiometers and cooling all critical components to physicaltemperatures approximating the CMB temperature. A linear model is used tocompare the output of each radiometer to a set of thermometers on theinstrument. Small corrections are made for the residual emission from theflight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE2 data alone show an extragalactic rise of $50\pm7$ mK at 3.3 GHz in additionto a CMB temperature of $2.730\pm .004$ K. Combining the ARCADE 2 data withdata from the literature shows a background power law spectrum of $T=1.26\pm0.09$ K $ u- u 0^{-2.60\pm 0.04}$ from 22 MHz to 10 GHz $ u 0=1$ GHzin addition to a CMB temperature of $2.725\pm .001$ K.



Author: D. J. Fixsen, A. Kogut, S. Levin, M. Limon, P. Lubin, P. Mirel, M. Seiffert, J. Singal, E. Wollack, T. Villela, C. A. Wuensche

Source: https://arxiv.org/



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