ISSN:0309-1929    

DOI:10.1080/03091929008219860

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Evidence from radio polarization measurements is reviewed that indicates that most galactic magnetic field structures fall into one of two categories: axisymmetric spiral and bisymmetric spiral. The resultant challenges to dynamo theorists is stated. Estimates of the magnetic field strengths based on equipartition of field and cosmic ray energies are given, but deviations from equipartition are inferred. Possible goals for future research are suggested.

ISSN:0309-1929    

DOI:10.1080/03091929008219861

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A new series of detailed observations of the Coma cluster of galaxies has been undertaken with the aim of better specifying the intergalactic gas component through high dynamic range, combined-telescope observations of the radio emission from the cluster which detect both the cluster-scaleandgalaxy-scale emission.

ISSN:0309-1929    

DOI:10.1080/03091929008219862

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Methods of measuring magnetic field strengths in astrophysics are reviewed. These determine that a magnetic field of 2–3μG lies approximately along the local spiral arm of the Galaxy. Faraday rotation measures indicate that abrupt field reversals occur in a number of directions. At the centre of the Galaxy, the field is vertical, i.e. perpendicular to the plane of the Galaxy.

ISSN:0309-1929    

DOI:10.1080/03091929008219863

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Methods of estimating the strength and direction of galactic magnetic fields from radio polarization measurements are reviewed. Particular attention is paid to the analysis of the Faraday rotation in order to derive the large scale magnetic field structure. Ways in which an axisymmetric spiral field structure can be observationally distinguished from a bisymmetric spiral structure are described, as are the ways in which field symmetric with respect to the galactic plane can be distinguished from those that are antisymmetric.

ISSN:0309-1929    

DOI:10.1080/03091929008219864

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The observational facts about magnetic fields in galactic halos are reviewed. The existence, origin and significance of poloidal field components are described. Observational evidence that magnetic fields channel winds from active galactic centres is discussed. Field strengths adduced from the radio polarizations of edge-on galaxies are given. Priorities for future research are suggested.

ISSN:0309-1929    

DOI:10.1080/03091929008219865

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Observations of the face-on galaxy NGC 6946 are inconsistent with a simple bisymmetric large-scale field structure confined to the galactic plane; the magnetic field must also possess significant three-dimensionality. The edge-on galaxy NGC 4945 has an active nucleus and a radio halo. Linear polarization maxima on each side of the central galactic plane suggest the presence of a strongly ordered poloidal magnetic field there.

ISSN:0309-1929    

DOI:10.1080/03091929008219866

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The detailed magnetic field structure of M31, as deduced from radio polarization measurements, is analyzed. The field closely follows a dust lane parallel to the most conspicuous optical spiral arm, but also exhibits three-dimensional arc-like deviations from the otherwise axisymmetric configuration.

ISSN:0309-1929    

DOI:10.1080/03091929008219867

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0309-1929    

DOI:10.1080/03091929008219868

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The possibility of detecting magnetic fields away from galactic disks or bars in bridges between interacting galaxies is discussed. In the case of the Magellanic Cloud system recent 2.4GHz measurements have confirmed fields in the SMC, LMC and the connecting bridge.

ISSN:0309-1929    

DOI:10.1080/03091929008219869

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor