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Title: MAGNETIC FIELDS IN A SAMPLE OF NEARBY SPIRAL GALAXIES

Both observations and modeling of magnetic fields in the diffuse interstellar gas of spiral galaxies are well developed, but the theory has been confronted with observations for only a handful of individual galaxies. There is now sufficient data to consider the statistical properties of galactic magnetic fields. We have collected data from the literature on the magnetic fields and interstellar media of 20 spiral galaxies, and tested for various physically motivated correlations between magnetic field and interstellar medium parameters. Clear correlations emerge between the total magnetic field strength and molecular gas density as well as the star formation rate. The magnetic pitch angle exhibits correlations with the total gas density, the star formation rate, and the strength of the axisymmetric component of the mean magnetic field. The total and mean magnetic field strengths exhibit a noticeable degree of correlation, suggesting a universal behavior of the degree of order in galactic magnetic fields. We also compare the predictions of galactic dynamo theory to observed magnetic field parameters and identify directions in which theory and observations might be usefully developed.
Authors:
 [1] ;  [2] ; ;  [3]
  1. Department of Astrophysics, Faculty of Science, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands)
  2. Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4 (Canada)
  3. School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)
Publication Date:
OSTI Identifier:
22364524
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 799; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AXIAL SYMMETRY; COMPARATIVE EVALUATIONS; CORRELATIONS; DENSITY; GALAXIES; INCLINATION; INTERSTELLAR MAGNETIC FIELDS; INTERSTELLAR SPACE; MAGNETOHYDRODYNAMICS; STARS