The Distribution of Radio Polarisation in Three Southern Galaxies

1991 ◽  
Vol 9 (2) ◽  
pp. 266-268
Author(s):  
J. I. Harnett ◽  
U. Klein ◽  
R. Wielebinski ◽  
R. F. Haynes
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Radio Telescope ◽  
Spiral Galaxies ◽  
Total Power ◽  
Transport Mechanisms ◽  
Contour Plots ◽  
Preliminary Study ◽  
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).

scholarly journals Magnetic Fields and the Interstellar Medium in Spiral Arms

1996 ◽  
Vol 171 ◽  
pp. 456-456
Author(s):  
M. Urbanik ◽  
M. Soida ◽  
R. Beck
Keyword(s):  
Magnetic Fields ◽  
Interstellar Medium ◽  
Radio Telescope ◽  
High Frequency ◽  
Spiral Galaxies ◽  
Total Power ◽  
Spiral Arms ◽  
Dust Lane ◽  
Radio Studies ◽  
Spiral Structures

We performed the high frequency radio studies of spiral galaxies using the 100 m MPIfR radio telescope at 10.55 GHz. Two objects: NGC 4254 and NGC 3627 possess perturbed spiral structures while two others, NGC 3521 and NGC 5055 are flocculent objects, lacking organized spiral patterns. NGC 3521 possesses also a peculiar dust lane. For NGC 4254, NGC 3627 and NGC 5055 deep polarization maps were made, for NGC 3521 the total power data only were analyzed (see Urbanik et al. 1989).

scholarly journals Galactic Winds and Magnetic Fields from Spiral Galaxies

1990 ◽  
Vol 140 ◽  
pp. 177-181 ◽  
Author(s):  
H.J. Völk ◽  
D. Breitschwerdt ◽  
J.F. McKenzie
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Mass Loss ◽  
Magnetic Structure ◽  
Essential Role ◽  
Spiral Galaxies ◽  
High Energy ◽  
Energy Component ◽  
Galactic Winds ◽  
High Energy Component

Concentrating on our own Galaxy we discuss the dynamics of the outer halo, its magnetic structure and the occurrence of a supersonic mass loss in the form of a Galactic wind. The cosmic rays, as the nonthermal high energy component, de facto not influenced by gravity, play an essential role in the wind dynamics.

scholarly journals CHANG-ES

2019 ◽  
Vol 623 ◽  
pp. A33 ◽  
Author(s):  
Y. Stein ◽  
R.-J. Dettmar ◽  
J. Irwin ◽  
R. Beck ◽  
M. Weżgowiec ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Large Scale ◽  
Spiral Galaxies ◽  
Cosmic Ray ◽  
Transport Processes ◽  
X Ray ◽  
Radio Data ◽  
The Magnetic Field

Context. The observation of total and linearly polarized synchrotron radiation of spiral galaxies in the radio continuum reveals the distribution and structure of their magnetic fields. By observing these, information about the proposed dynamo processes that preserve the large-scale magnetic fields in spiral galaxies can be gained. Additionally, by analyzing the synchrotron intensity, the transport processes of cosmic rays into the halo of edge-on spiral galaxies can be investigated. Aims. We analyze the magnetic field geometry and the transport processes of the cosmic rays of the edge-on spiral starburst galaxy NGC 4666 from CHANG-ES radio data in two frequencies; 6 GHz (C-band) and 1.5 GHz (L-band). Supplementary X-ray data are used to investigate the hot gas in NGC 4666. Methods. We determine the radio scale heights of total power emission at both frequencies for this galaxy. We show the magnetic field orientations derived from the polarization data. Using rotation measure (RM) synthesis we further study the behavior of the RM values along the disk in C-band to investigate the large-scale magnetic-field pattern. We use the revised equipartition formula to calculate a map of the magnetic field strength. Furthermore, we model the processes of cosmic-ray transport into the halo with the 1D SPINNAKER model. Results. The extended radio halo of NGC 4666 is box-shaped and is probably produced by the previously observed supernova-driven superwind. This is supported by our finding of an advective cosmic-ray transport such as that expected for a galactic wind. The scale-height analysis revealed an asymmetric halo above and below the disk as well as between the two sides of the major axis. A central point source as well as a bubble structure is seen in the radio data for the first time. Our X-ray data show a box-shaped hot halo around NGC 4666 and furthermore confirm the AGN nature of the central source. NGC 4666 has a large-scale X-shaped magnetic field in the halo, as has been observed in other edge-on galaxies. The analysis furthermore revealed that the disk of NGC 4666 shows hints of field reversals along its radius, which is the first detection of this phenomenon in an external galaxy.

scholarly journals The measurement of the energy of cosmic rays - II—The curvature measurements and the energy spectrum

1936 ◽  
Vol 154 (883) ◽  
pp. 573-587 ◽  
Keyword(s):  
Magnetic Field ◽  
Energy Spectrum ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Strong Magnetic Fields ◽  
The Earth ◽  
Primary Particles ◽  
Curvature Measurements

Both the penetrating power of the cosmic rays through material ab­sorbers and their ability to reach the earth in spite of its magnetic field, make it certain that the energy of many of the primary particles must reach at least 10 11 e-volts. However, the energy measurements by Kunze, and by Anderson, using cloud chambers in strong magnetic fields, have extended only to about 5 x 10 9 e-volts. Particles of greater energy were reported, but the curvature of their tracks was too small to be measured with certainty. We have extended these energy measurements to somewhat higher energies, using a large electro-magnet specially built for the purpose and described in Part I. As used in these experiments, the magnet allowed the photography of tracks 17 cm long in a field of about 14,000 gauss. The magnet weighed about 11,000 kilos and used a power of 25 kilowatts.

scholarly journals Depth of shower maximum and mass composition of cosmic rays from 50 PeV to 2 EeV measured with the LOFAR radio telescope

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
A. Corstanje ◽  
S. Buitink ◽  
H. Falcke ◽  
B. M. Hare ◽  
J. R. Hörandel ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Radio Telescope ◽  
Mass Composition ◽  
Shower Maximum

scholarly journals The Origin and Dynamical Effects of the Magnetic Fields and Cosmic Rays in the Disk of the Galaxy

1970 ◽  
Vol 39 ◽  
pp. 168-183
Author(s):  
E. N. Parker
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Magnetic Fields ◽  
Dynamical Behavior ◽  
Cosmic Ray ◽  
Interested Reader ◽  
Written Text ◽  
The Galaxy ◽  
Basic Ideas ◽  
The Magnetic Field

The topic of this presentation is the origin and dynamical behavior of the magnetic field and cosmic-ray gas in the disk of the Galaxy. In the space available I can do no more than mention the ideas that have been developed, with but little explanation and discussion. To make up for this inadequacy I have tried to give a complete list of references in the written text, so that the interested reader can pursue the points in depth (in particular see the review articles Parker, 1968a, 1969a, 1970). My purpose here is twofold, to outline for you the calculations and ideas that have developed thus far, and to indicate the uncertainties that remain. The basic ideas are sound, I think, but, when we come to the details, there are so many theoretical alternatives that need yet to be explored and so much that is not yet made clear by observations.

ENERGY ORDERING EFFECTS IN THE ARRIVAL DIRECTIONS OF ULTRA-HIGH ENERGY COSMIC RAYS MEASURED BY THE PIERRE AUGER OBSERVATORY

2011 ◽  
Vol 20 (supp02) ◽  
pp. 50-56
Author(s):  
◽  
PETER SCHIFFER
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Charged Particles ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
Ordering Effects ◽  
Arrival Directions

The Pierre Auger Observatory is the world's largest experiment for the measurement of ultra-high energy cosmic rays (UHECRs). These UHECRs are assumed to be to be charged particles, and thus are deflected in cosmic magnetic fields. Recent results of the Pierre Auger Observatory addressing the complex of energy ordering of the UHECRs arrival directions are reviewed in this contribution. So far no significant energy ordering has been observed.

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