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Title: ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE

Abstract

Rotation measures (RMs) of pulsars and extragalactic point sources have been known to reveal large-scale antisymmetries in the Faraday rotation sky with respect to the Galactic plane and halo that have been interpreted as signatures of the mean magnetic field in the Galactic halo. We describe Faraday rotation measurements of the diffuse Galactic polarized radio emission over a large region in the northern Galactic hemisphere. Through application of RM synthesis we achieve sensitive Faraday rotation maps with high angular resolution, capable of revealing fine-scale structures of {approx}1{sup 0} in the Faraday rotation sky. Our analysis suggests that the observed antisymmetry in the Faraday rotation sky at b>0{sup 0} is dominated by the magnetic field around a local H I bubble at a distance of 100 pc, and not by the magnetic field of the Galactic halo. We derive physical properties of the magnetic field of this shell, which we find to be 20-34 {mu}G strong. It is clear that the diffuse polarized radio emission contains important information about the local magneto-ionic medium, which cannot yet be derived from Faraday RMs of extragalactic sources or pulsars alone.

Authors:
;  [1];  [2]; ;  [3];  [4];  [5];  [6];  [7]
  1. Dominion Radio Astrophysical Observatory, HIA-NRC, 717 White Lake Road, P.O. Box 248, Penticton, BC, V2A 6J9 (Canada)
  2. School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)
  3. ATNF-CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW 1710 (Australia)
  4. Physics Department, Private Bag 21, University of Tasmania, Hobart, TAS 7001 (Australia)
  5. Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia)
  6. ASTRON, P.O. Box 2, 7990 AA Dwingeloo (Netherlands)
  7. Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, 53121, Bonn (Germany)
Publication Date:
OSTI Identifier:
21452669
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 724; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/724/1/L48; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; EMISSION; FARADAY EFFECT; GALAXIES; MAGNETIC FIELDS; PHYSICAL PROPERTIES; POINT SOURCES; POLARIZATION; PULSARS; COSMIC RADIO SOURCES; PHYSICS; RADIATION SOURCES

Citation Formats

Wolleben, M, Landecker, T L, Fletcher, A, Carretti, E, McClure-Griffiths, N, Dickey, J M, Gaensler, B M, Haverkorn, M, Reich, W, and Taylor, A. R., E-mail: maik.wolleben@nrc.gc.c. ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE. United States: N. p., 2010. Web. doi:10.1088/2041-8205/724/1/L48.
Wolleben, M, Landecker, T L, Fletcher, A, Carretti, E, McClure-Griffiths, N, Dickey, J M, Gaensler, B M, Haverkorn, M, Reich, W, & Taylor, A. R., E-mail: maik.wolleben@nrc.gc.c. ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE. United States. https://doi.org/10.1088/2041-8205/724/1/L48
Wolleben, M, Landecker, T L, Fletcher, A, Carretti, E, McClure-Griffiths, N, Dickey, J M, Gaensler, B M, Haverkorn, M, Reich, W, and Taylor, A. R., E-mail: maik.wolleben@nrc.gc.c. 2010. "ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE". United States. https://doi.org/10.1088/2041-8205/724/1/L48.
@article{osti_21452669,
title = {ANTISYMMETRY IN THE FARADAY ROTATION SKY CAUSED BY A NEARBY MAGNETIZED BUBBLE},
author = {Wolleben, M and Landecker, T L and Fletcher, A and Carretti, E and McClure-Griffiths, N and Dickey, J M and Gaensler, B M and Haverkorn, M and Reich, W and Taylor, A. R., E-mail: maik.wolleben@nrc.gc.c},
abstractNote = {Rotation measures (RMs) of pulsars and extragalactic point sources have been known to reveal large-scale antisymmetries in the Faraday rotation sky with respect to the Galactic plane and halo that have been interpreted as signatures of the mean magnetic field in the Galactic halo. We describe Faraday rotation measurements of the diffuse Galactic polarized radio emission over a large region in the northern Galactic hemisphere. Through application of RM synthesis we achieve sensitive Faraday rotation maps with high angular resolution, capable of revealing fine-scale structures of {approx}1{sup 0} in the Faraday rotation sky. Our analysis suggests that the observed antisymmetry in the Faraday rotation sky at b>0{sup 0} is dominated by the magnetic field around a local H I bubble at a distance of 100 pc, and not by the magnetic field of the Galactic halo. We derive physical properties of the magnetic field of this shell, which we find to be 20-34 {mu}G strong. It is clear that the diffuse polarized radio emission contains important information about the local magneto-ionic medium, which cannot yet be derived from Faraday RMs of extragalactic sources or pulsars alone.},
doi = {10.1088/2041-8205/724/1/L48},
url = {https://www.osti.gov/biblio/21452669}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 724,
place = {United States},
year = {Sat Nov 20 00:00:00 EST 2010},
month = {Sat Nov 20 00:00:00 EST 2010}
}