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

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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A New Technique for the Measurement of Stellar Magnetic Fields: First Results

Activity in Cool Star Envelopes - Astrophysics and Space Science Library ◽

10.1007/978-94-009-2951-7_5 ◽

1988 ◽

pp. 39-43 ◽

Cited By ~ 2

Author(s):

S. K. Solanki ◽

G. Mathys

Keyword(s):

Magnetic Fields ◽

New Technique ◽

First Results ◽

A New Technique ◽

Stellar Magnetic Fields

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Experimental Study of the Orientation of Magnetic Fields in the Corona

Symposium - International Astronomical Union ◽

10.1017/s0074180900023044 ◽

1971 ◽

Vol 43 ◽

pp. 580-587 ◽

Cited By ~ 6

Author(s):

P. Charvin

Keyword(s):

Magnetic Field ◽

Experimental Study ◽

Magnetic Fields ◽

Large Scale ◽

Coronal Line ◽

Magnetic Structures ◽

Polarization Measurements ◽

First Results

We present polarization measurements obtained in 1970 in the green coronal line with a new coronameter located at the Pic du Midi. The analysis of these data has been conducted with the theory given by the writer in 1964 and 1965. It appears that magnetic field orientations in the Corona can be deduced from the above measurements. First results showing large scale magnetic structures are presented.

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Turbulence and magnetic fields in molecular clouds

Symposium - International Astronomical Union ◽

10.1017/s0074180900239430 ◽

1991 ◽

Vol 147 ◽

pp. 83-92

Author(s):

R. N. Henriksen

Keyword(s):

Magnetic Fields ◽

Wavelet Analysis ◽

Molecular Clouds ◽

Fractal Structure ◽

Compressible Turbulence ◽

Dynamo Theory ◽

First Results ◽

Self Similar

in this paper I first review some of the simple structural concepts associated with compressible turbulence. In particular the hierarchical or self-similar fractal structure to be expected is formulated in a manner readily compared to the observations, and to previous work. In the next section I present the first results of a wavelet analysis on molecular clouds, which seem to comfirm the hierarchical scaling. I conclude with an extention of the theory to include magnetic fields. This latter theory represents an alternative to the more conventional dynamo theory.

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SPIRou: NIR velocimetry and spectropolarimetry at the CFHT

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2569 ◽

2020 ◽

Vol 498 (4) ◽

pp. 5684-5703 ◽

Cited By ~ 1

Author(s):

J-F Donati ◽

D Kouach ◽

C Moutou ◽

R Doyon ◽

X Delfosse ◽

...

Keyword(s):

Magnetic Fields ◽

Near Infrared ◽

Planetary Systems ◽

Young Stars ◽

Central Position ◽

M Dwarfs ◽

Testing Phase ◽

First Results ◽

New Generation ◽

Final Acceptance

ABSTRACT This paper presents an overview of SPIRou, the new-generation near-infrared spectropolarimeter/precision velocimeter recently installed on the 3.6-m Canada–France–Hawaii Telescope (CFHT). Starting from the two main science goals, i.e., the quest for planetary systems around nearby M dwarfs and the study of magnetized star/planet formation, we outline the instrument concept that was designed to efficiently address these forefront topics, and detail the in-lab and on-sky instrument performances measured throughout the intensive testing phase that SPIRou was submitted to before passing the final acceptance review in early 2019 and initiating science observations. With a central position among the newly started programmes, the SPIRou Legacy Survey (SLS) Large Programme was allocated 300 CFHT nights until at least mid 2022. We also briefly describe a few of the first results obtained in the various science topics that SPIRou started investigating, focusing in particular on planetary systems of nearby M dwarfs, transiting exoplanets and their atmospheres, magnetic fields of young stars, but also on alternate science goals like the atmospheres of M dwarfs and the Earth’s atmosphere. We finally conclude on the key role that SPIRou and the CFHT can play in coordination with forthcoming major facilities like the JWST, the ELTs, PLATO, and ARIEL over the decade.

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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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Primordial magnetism in CMB B modes

Canadian Journal of Physics ◽

10.1139/cjp-2012-0401 ◽

2013 ◽

Vol 91 (6) ◽

pp. 451-454 ◽

Cited By ~ 5

Author(s):

Levon Pogosian ◽

Tanmay Vachaspati ◽

Amit Yadav

Keyword(s):

Magnetic Fields ◽

Cosmic Microwave Background ◽

Frequency Dependence ◽

Faraday Rotation ◽

Characteristic Frequency ◽

Mode Coupling ◽

Microwave Background ◽

Small Scales ◽

Cmb Polarization ◽

Primordial Magnetic Fields

Cosmic microwave background (CMB) polarization B modes induced by Faraday rotation (FR) can provide a distinctive signature of primordial magnetic fields because of their characteristic frequency dependence and because they are only weakly damped on small scales. FR also leads to mode-coupling correlations between the E- and B-type polarizations and between the temperature and the B mode. These additional correlations can further help distinguish magnetic fields from other sources of B modes. We review the FR-induced CMB signatures and present the constraints on primordial magnetism that can be expected from upcoming CMB experiments. Our results suggest that FR of CMB will be a promising probe of primordial magnetic fields.

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Magnetic Guiding with Permanent Magnets: Concept, Realization and Applications to Nanoparticles and Cells

Cells ◽

10.3390/cells10102708 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2708

Author(s):

Peter Blümler

Keyword(s):

Magnetic Fields ◽

Permanent Magnets ◽

Imaging Techniques ◽

Superparamagnetic Nanoparticles ◽

Force Generation ◽

Magnetic Imaging ◽

Nanoparticle Dispersions ◽

First Results ◽

Macroscopic Objects ◽

Orientation Movement

The idea of remote magnetic guiding is developed from the underlying physics of a concept that allows for bijective force generation over the inner volume of magnet systems. This concept can equally be implemented by electro- or permanent magnets. Here, permanent magnets are in the focus because they offer many advantages. The equations of magnetic fields and forces as well as velocities are derived in detail and physical limits are discussed. The special hydrodynamics of nanoparticle dispersions under these circumstances is reviewed and related to technical constraints. The possibility of 3D guiding and magnetic imaging techniques are discussed. Finally, the first results in guiding macroscopic objects, superparamagnetic nanoparticles, and cells with incorporated nanoparticles are presented. The constructed magnet systems allow for orientation, movement, and acceleration of magnetic objects and, in principle, can be scaled up to human size.

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