Is there an unaccounted for excess in the extragalactic cosmic radio background?

Subrahmanyan, Ravi; Cowsik, Ramanath

Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/5947

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DC Field	Value	Language
dc.contributor.author	Subrahmanyan, Ravi	-
dc.contributor.author	Cowsik, Ramanath	-
dc.date.accessioned	2014-08-06T07:26:41Z	-
dc.date.available	2014-08-06T07:26:41Z	-
dc.date.issued	2013-10-10	-
dc.identifier.citation	Astrophysical Journal, 2013, Vol.776, p42	en
dc.identifier.issn	0004-637X	-
dc.identifier.issn	1538-4357-(Online)	-
dc.identifier.uri	http://hdl.handle.net/2289/5947	-
dc.description	Restricted Access	en
dc.description.abstract	Analyses of the distribution of absolute brightness temperature over the radio sky have recently led to suggestions that there exists a substantial unexplained extragalactic radio background. Consequently, there have been numerous attempts to place constraints on plausible origins of this "excess." We suggest here that this expectation of a large extragalactic background, over and above that contributed by the sources observed in the surveys, is based on an extremely simple geometry adopted to model the Galactic emission and the procedure adopted in the estimation of the extragalactic contribution. In this paper, we derive the extragalactic radio background from wide-field radio images using a more realistic modeling of the Galactic emission and decompose the sky maps at 150, 408, and 1420 MHz into anisotropic Galactic and isotropic extragalactic components. The anisotropic Galactic component is assumed to arise from a highly flattened spheroid representing the thick disk, embedded in a spherical halo, both centered at the Galactic center, along with Galactic sources, filamentary structures, and Galactic loops and spurs. All components are constrained to be positive and the optimization scheme minimizes the sky area occupied by the complex filaments. We show that in contrast with simple modeling of Galactic emission as a plane parallel slab, the more realistic modeling yields estimates for the uniform extragalactic brightness that are consistent with expectations from known extragalactic radio source populations.	en
dc.language.iso	en	en
dc.publisher	IOP Sciences for The American Astronomical Society	en
dc.relation.uri	http://adsabs.harvard.edu/abs/2013ApJ...776...42S	en
dc.relation.uri	http://arxiv.org/abs/1305.7060	en
dc.relation.uri	http://dx.doi.org/10.1088/0004-637X/776/1/42	en
dc.rights	2013 American Astronomical Society, This article may be downloaded for personal use only. Any other use requires prior permission of the author and The American Astronomical Society	en
dc.subject	Radio continuum	en
dc.title	Is there an unaccounted for excess in the extragalactic cosmic radio background?	en
dc.type	Article	en
Appears in Collections:	Research Papers (A&A)

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