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Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/6639
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dc.contributor.authorLenc, E.-
dc.contributor.authorDeshpande, A.A.-
dc.contributor.authorDwarakanath, K.S.-
dc.contributor.authorPaul, Sourabh-
dc.contributor.authorPrabu, T.-
dc.contributor.authorUdaya Shankar, N.-
dc.contributor.authorSethi, S.K.-
dc.contributor.authorSrivani, K.S.-
dc.contributor.authorSubrahmanyan, Ravi-
dc.contributor.author+50 Co-authors-
dc.date.accessioned2017-05-06T11:50:25Z-
dc.date.available2017-05-06T11:50:25Z-
dc.date.issued2016-10-10-
dc.identifier.citationAstrophysical Journal, 2016, Vol. 830, p 38en_US
dc.identifier.issn0004-637X-
dc.identifier.issn1538-4357-(Online)-
dc.identifier.urihttp://hdl.handle.net/2289/6639-
dc.descriptionOpen Accessen_US
dc.description.abstractWe present deep polarimetric observations at 154 MHz with the Murchison Widefield Array (MWA), covering 625 deg2 centered on α = 0hand δ = −27°. The sensitivity available in our deep observations allows an in-band, frequency-dependent analysis of polarized structure for the first time at long wavelengths. Our analysis suggests that the polarized structures are dominated by intrinsic emission but may also have a foreground Faraday screen component. At these wavelengths, the compactness of the MWA baseline distribution provides excellent snapshot sensitivity to large-scale structure. The observations are sensitive to diffuse polarized emission at ~54' resolution with a sensitivity of 5.9 mJy beam−1 and compact polarized sources at ~2farcm4 resolution with a sensitivity of 2.3 mJy beam−1 for a subset (400 deg2) of this field. The sensitivity allows the effect of ionospheric Faraday rotation to be spatially and temporally measured directly from the diffuse polarized background. Our observations reveal large-scale structures (~1°–8° in extent) in linear polarization clearly detectable in ~2 minute snapshots, which would remain undetectable by interferometers with minimum baseline lengths of >110 m at 154 MHz. The brightness temperature of these structures is on average 4 K in polarized intensity, peaking at 11 K. Rotation measure synthesis reveals that the structures have Faraday depths ranging from −2 to 10 rad m−2 with a large fraction peaking at approximately +1 rad m−2. We estimate a distance of 51 ± 20 pc to the polarized emission based on measurements of the in-field pulsar J2330–2005. We detect four extragalactic linearly polarized point sources within the field in our compact source survey. Based on the known polarized source population at 1.4 GHz and non-detections at 154 MHz, we estimate an upper limit on the depolarization ratio of 0.08 from 1.4 GHz to 154 MHz.en_US
dc.language.isoenen_US
dc.publisherIOP Sciences for The American Astronomical Societyen_US
dc.relation.urihttp://adsabs.harvard.edu/abs/2016ApJ...830...38Len_US
dc.relation.urihttp://arxiv.org/abs/1607.05779en_US
dc.relation.urihttp://dx.doi.org/10.3847/0004-637X/830/1/38en_US
dc.rights2016, The American Astronomical Society.en_US
dc.titleLow-frequency observations of linearly polarized structures in the interstellar medium near the south galactic poleen_US
dc.typeArticleen_US
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