Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/6254
Full metadata record
DC FieldValueLanguage
dc.contributor.authorPatra, Nipanjana-
dc.contributor.authorSubrahmanyan, Ravi-
dc.contributor.authorSethi, S.K.-
dc.contributor.authorUdaya Shankar, N.-
dc.contributor.authorRaghunathan, A.-
dc.date.accessioned2015-07-25T07:12:14Z-
dc.date.available2015-07-25T07:12:14Z-
dc.date.issued2015-03-10-
dc.identifier.citationAstrophysical Journal, 2015, Vol. 801, p 138en
dc.identifier.issn0004-637X-
dc.identifier.issn1538-4357-(Online)-
dc.identifier.urihttp://hdl.handle.net/2289/6254-
dc.descriptionRestricted Access. An open-access version is available at arXiv.org (one of the alternative locations)en
dc.description.abstractSARAS is a correlation spectrometer connected to a frequency independent antenna that is purpose-designed for precision measurements of the radio background at long wavelengths. The design, calibration, and observing strategies admit solutions for the internal additive contributions to the radiometer response, and hence a separation of these contaminants from the antenna temperature. We present here a wideband measurement of the radio sky spectrum by SARAS that provides an accurate measurement of the absolute brightness and spectral index between 110 and 175 MHz. Accuracy in the measurement of absolute sky brightness is limited by systematic errors of magnitude 1.2%; errors in calibration and in the joint estimation of sky and system model parameters are relatively smaller. We use this wide-angle measurement of the sky brightness using the precision wide-band dipole antenna to provide an improved absolute calibration for the 150 MHz all-sky map of Landecker and Wielebinski: subtracting an offset of 21.4 K and scaling by a factor of 1.05 will reduce the overall offset error to 8 K (from 50 K) and scale error to 0.8% (from 5%). The SARAS measurement of the temperature spectral index is in the range −2.3 to −2.45 in the 110–175 MHz band and indicates that the region toward the Galactic bulge has a relatively flatter index.en
dc.language.isoenen
dc.publisherIOP Sciences for The American Astronomical Societyen
dc.relation.urihttp://adsabs.harvard.edu/abs/2015ApJ...801..138Pen
dc.relation.urihttp://arxiv.org/abs/1412.7762en
dc.relation.urihttp://dx.doi.org/10.1088/0004-637X/801/2/138en
dc.rights2015, The American Astronomical Society.en
dc.titleSARAS measurement of the radio background at long wavelengthsen
dc.typeArticleen
Appears in Collections:Research Papers (A&A)

Files in This Item:
File Description SizeFormat 
2015_AstroPhyJ_801_138.pdf
  Restricted Access
Restricted Access 1.76 MBAdobe PDFView/Open Request a copy


Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.