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Lookup NU author(s): Dr Christopher Hales
This is the authors' accepted manuscript of an article that has been published in its final definitive form by Institute of Physics Publishing, 2016.
For re-use rights please refer to the publisher's terms and conditions.
© 2016. The American Astronomical Society. All rights reserved.We empirically evaluate the scheme proposed by Lieu & Duan in which the light curve of a time-steady radio source is predicted to exhibit increased variability on a characteristic timescale set by the sightline's electron column density. Application to extragalactic sources is of significant appeal, as it would enable a unique and reliable probe of cosmic baryons. We examine temporal power spectra for 3C 84, observed at 1.7 GHz with the Karl G. Jansky Very Large Array and the Robert C. Byrd Green Bank Telescope. These data constrain the ratio between standard deviation and mean intensity for 3C 84 to less than 0.05% at temporal frequencies ranging between 0.1 and 200 Hz. This limit is 3 orders of magnitude below the variability predicted by Lieu & Duan and is in accord with theoretical arguments presented by Hirata & McQuinn rebutting electron density dependence. We identify other spectral features in the data consistent with the slow solar wind, a coronal mass ejection, and the ionosphere.
Author(s): Hales CA, Max-Moerbeck W, Roshi DA, Rupen MP
Publication type: Article
Publication status: Published
Journal: Astrophysical Journal
Online publication date: 25/05/2016
Acceptance date: 10/04/2016
Date deposited: 30/06/2017
ISSN (print): 0004-637X
ISSN (electronic): 1538-4357
Publisher: Institute of Physics Publishing
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