Poloidal Magnetic Fields in Galactic Central Regions

AbstractWe are studying the distribution and morphology of magnetic fields in southern face-on and edge-on galaxies with the intention of clarifying the distribution, lifetimes and transport mechanisms of cosmic rays, and investigating the intensity and orientation of the disc, halo and poloidal magnetic fields. As a preliminary study, before the Australia Telescope was available, we observed a sample of well-known southern spiral galaxies with the Parkes radio telescope.Here, we present the resulting polarisation images for three galaxies, NGC 253, M 83 and NGC 4945, which were observed at 4.75 GHz and 8.55 GHz. The corresponding total power contour plots have been already published by Harnett et al. (1989a, 1990).

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The Toroidal and Poloidal Coil Systems of JET

Proceedings of the Institution of Mechanical Engineers Part A Power and Process Engineering ◽

10.1243/pime_proc_1986_200_012_02 ◽

1986 ◽

Vol 200 (2) ◽

pp. 81-94 ◽

Cited By ~ 2

Author(s):

J R Last

Keyword(s):

Magnetic Fields ◽

Design And Manufacture ◽

Poloidal Magnetic Fields

This paper describes the design and manufacture of coils to produce the toroidal and poloidal magnetic fields of the JET (Joint European Torus) Tokamak fusion project.

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Observations of Galactic Magnetic Fields

Highlights of Astronomy ◽

10.1017/s153929960001474x ◽

2002 ◽

Vol 12 ◽

pp. 712-715 ◽

Cited By ~ 1

Author(s):

Rainer Beck

Keyword(s):

Magnetic Fields ◽

Large Scale ◽

Density Wave ◽

Upstream Region ◽

Galactic Magnetic Fields ◽

Barred Galaxies ◽

Angular Momentum Transport ◽

Central Regions ◽

Spiral Structures ◽

Field Lines

AbstractMagnetic fields are anchored in gas clouds. Field lines are tangled in spiral arms, but highly regularbetweenthe arms. The similarity of pitch angles between gaseous and magnetic arms suggests a coupling between the density wave and the magnetic wave. Observations of large-scale patterns in Faraday rotation favour a dynamo origin of the regular fields. Fields in barred galaxies do not reveal the strong shearing shocks observed in the cold gas, but swing smoothly from the upstream region into the bar. Magnetic fields are important for the dynamics of gas clouds, for the formation of spiral structures, bars and halos, and for mass and angular momentum transport in central regions.

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The continuous spectrum of MHD waves in 2D solar loops and arcades. First results on poloidal mode coupling for poloidal magnetic fields

Solar Physics ◽

10.1007/bf00160652 ◽

1987 ◽

Vol 109 (2) ◽

pp. 265-286 ◽

Cited By ~ 15

Author(s):

S. Poedts ◽

M. Goossens

Keyword(s):

Magnetic Fields ◽

Continuous Spectrum ◽

Mode Coupling ◽

Mhd Waves ◽

First Results ◽

Solar Loops ◽

Poloidal Magnetic Fields

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Measurements of Cosmic Magnetism with LOFAR and SKA

Advances in Radio Science ◽

10.5194/ars-5-399-2007 ◽

2007 ◽

Vol 5 ◽

pp. 399-405 ◽

Cited By ~ 9

Author(s):

R. Beck

Keyword(s):

Magnetic Fields ◽

Interstellar Medium ◽

Milky Way ◽

Intergalactic Medium ◽

Low Frequency ◽

Radio Telescopes ◽

New Era ◽

Origin And Evolution ◽

Central Regions ◽

Nearby Galaxies

Abstract. The origin of magnetic fields in stars, galaxies and clusters is an open problem in astrophysics. The next-generation radio telescopes Low Frequency Array (LOFAR) and Square Kilometre Array (SKA) will revolutionize the study of cosmic magnetism. "The origin and evolution of cosmic magnetism" is a key science project for SKA. The planned all-sky survey of Faraday rotation measures (RM) at 1.4 GHz will be used to model the structure and strength of the magnetic fields in the intergalactic medium, the interstellar medium of intervening galaxies, and in the Milky Way. A complementary survey of selected regions at around 200 MHz is planned as a key project for LOFAR. Spectro-polarimetry applied to the large number of spectral channels available for LOFAR and SKA will allow to separate RM components from distinct foreground and background regions and to perform 3-D Faraday tomography of the interstellar medium of the Milky Way and nearby galaxies. – Deep polarization mapping with LOFAR and SKA will open a new era also in the observation of synchrotron emission from magnetic fields. LOFAR's sensitivity will allow to map the structure of weak, extended magnetic fields in the halos of galaxies, in galaxy clusters, and possibly in the intergalactic medium. Polarization observations with SKA at higher frequencies (1–10 GHz) will show the detailed magnetic field structure within the disks and central regions of galaxies, with much higher angular resolution than present-day radio telescopes.

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