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An Anomalous Component of Galactic Emission

Authors :
T. J. Pearson
A. C. S. Readhead
Steven T. Myers
Erik M. Leitch
Source :
Scopus-Elsevier
Publication Year :
1997
Publisher :
American Astronomical Society, 1997.

Abstract

We present results from microwave background observations at the Owens Valley Radio Observatory. These observations, at 14.5 and 32 GHz, are designed to detect intrinsic anisotropy on scales of 7'. After point source removal, we detect significant emission with temperature spectral index beta ~ -2 towards the North Celestial Pole (NCP). Comparison of our data with the IRAS 100 micron map of the same fields reveals a strong correlation between this emission and the infrared dust emission. From the lack of detectable H-alpha emission, we conclude that the signals are consistent either with flat-spectrum synchrotron radiation, or with free-free emission from T_e ~ 10^6 K gas, probably associated with a large HI feature known as the NCP Loop. Assuming beta = -2.2, our data indicate a conversion T_f/I_(100 micron) = 0.075*nu(GHz)^-2.2 K/(MJy/sr). The detection of such a component suggests that we should be cautious in any assumptions made regarding foregrounds when designing experiments to map the microwave background radiation.<br />6 pages, Latex, 3 Postscript figures, uses aas2pp4.sty

Details

ISSN :
0004637X
Volume :
486
Database :
OpenAIRE
Journal :
The Astrophysical Journal
Accession number :
edsair.doi.dedup.....bc9d35da63f1f07bf5a1db6e1a6548e9
Full Text :
https://doi.org/10.1086/310823