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The global magneto-ionic medium survey: a faraday depth survey of the northern sky covering 1280-1750 mhz


Wolleben, M and Landecker, TL and Douglas, KA and Gray, AD and Ordog, A and Dickey, JM and Hill, AS and Carretti, E and Brown, JC and Gaensler, BM and Han, JL and Haverkorn, M and Kothes, R and Leahy, JP and McClure-Griffiths, N and McConnell, D and Reich, W and Taylor, AR and Thomson, AJM and West, JL, The global magneto-ionic medium survey: a faraday depth survey of the northern sky covering 1280-1750 mhz, Astronomical Journal, 162, (1) Article 35. ISSN 0004-6256 (2021) [Refereed Article]

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DOI: doi:10.3847/1538-3881/abf7c1


The Galactic interstellar medium hosts a significant magnetic field, which can be probed through the synchrotron emission produced from its interaction with relativistic electrons. Linearly polarized synchrotron emission is generated throughout the Galaxy and, at longer wavelengths, modified along nearly every path by Faraday rotation in the intervening magneto-ionic medium. Full characterization of the polarized emission requires wideband observations with many frequency channels. We have surveyed polarized radio emission from the Northern sky over the range 1280-1750 MHz, with channel width 236.8 kHz, using the John A. Galt Telescope (diameter 25.6 m) at the Dominion Radio Astrophysical Observatory, as part of the Global Magneto-Ionic Medium Survey. The survey covered 72% of the sky, decl. -30degree to +87degree at all R.A. The intensity scale was absolutely calibrated, based on the flux density and spectral index of Cygnus A. Polarization angle was calibrated using the extended polarized emission of the Fan Region. Data are presented as brightness temperatures with angular resolution 40'. Sensitivity in Stokes Q and U is 45 mK rms in a 1.18 MHz band. We have applied rotation measure synthesis to the data to obtain a Faraday depth cube of resolution 150 rad m-2 and sensitivity 3 mK rms of polarized intensity. Features in Faraday depth up to a width of 110 rad m-2 are represented. The maximum detectable Faraday depth is +-2 x 104 rad m-2. The survey data are available at the Canadian Astronomy Data Centre.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Galactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Dickey, JM (Professor John Dickey)
ID Code:152301
Year Published:2021
Web of Science® Times Cited:4
Deposited By:Plant Science
Deposited On:2022-08-16
Last Modified:2022-09-15

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