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Accession Number
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N20120013031
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Title
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Synchrotron Spectral Curvature from 22 MHZ to 23 GHZ.
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Publication Date
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Feb 2012
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Media Count
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5p
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Personal Author
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A. J. Kogut
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Abstract
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We combine surveys of the radio sky at frequencies 22 MHz to 1.4 GHz with data from the ARCADE-2 instrument at frequencies 3 GHz to 10 GHz to characterize the frequency spectrum of diffuse synchrotron emission in the Galaxy. The radio spectrum steepens with frequency from 22 MHz to 10 GHz. The projected spectral index at 23 GHz derived from the low-frequency data agrees well with independent measurements using only data at frequencies 23 GHz and above. Comparing the spectral index at 23 GHz to the value from previously published analyses allows extension of the model to higher frequencies. The combined data are consistent with a power-law index beta = -2.64 +/-= 0.03 at 0.31 GHz, steepening by an amount of Delta-beta = 0.07 every octave in frequency. Comparison of the radio data to models including the cosmic-ray energy spectrum suggests that any break in the synchrotron spectrum must occur at frequencies above 23 GHz.
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Keywords
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Curvature
Nonthermal radiation
Radio astronomy
Radio spectra
Synchrotron radiation
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Source Agency
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National Aeronautics and Space Administration
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NTIS Subject Category
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54B - Astronomy & Celestial Mechanics
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Corporate Author
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Goddard Space Flight Center, Greenbelt, MD.
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Document Type
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Journal article
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Title Note
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N/A
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NTIS Issue Number
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1303
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Contract Number
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N/A
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