The WENSS and Dwingeloo surveys and the Galactic magnetic field
| Autor: | A. G. de Bruyn, Peter Katgert, D. H. F. M. Schnitzeler, M. Haverkorn |
|---|---|
| Přispěvatelé: | Astronomy |
| Rok vydání: | 2006 |
| Předmět: |
ISM : structure
FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics magnetic fields REGION symbols.namesake MULTIFREQUENCY POLARIMETRY Periodic data techniques : miscellaneous Perpendicular SCALE Astrophysics::Galaxy Astrophysics Physics LINEAR-POLARIZATION Toy model Brewster's angle UNDERSTANDING RADIO POLARIMETRY Astrophysics (astro-ph) Astronomy and Astrophysics techniques : polarimetric PLANE Galactic plane FARADAY-ROTATION Magnetic field ISM : magnetic fields Synchrotron emission 350 MHZ Interferometry ROTATION MEASURES Space and Planetary Science symbols CONTINUUM SURVEY radio continuum : ISM |
| Zdroj: | Astronomy & astrophysics, 461(3), 963-976. EDP Sciences |
| ISSN: | 0004-6361 |
| DOI: | 10.48550/arxiv.astro-ph/0610568 |
| Popis: | In this paper we use the diffuse Galactic synchrotron emission to study the properties of the Galactic magnetic field. We combined data from the low-frequency WENSS survey with single-dish observations carried out by Brouw and Spoelstra to (partially) fill in the central gap in the (u,v) plane that is missing from the interferometer data. The small bandwidth of the WENSS data meant that we could not determine rotation measures (RM) directly. Instead we interpreted the polarization angle gradients that we derived as gradients in RM, and to do this we found a new way to efficiently and reliably fit linear gradients to periodic data. RM are available for the single-dish observations, and we found that we have to rescale these single-dish RM to match the RM gradients that we derive from the combined WENSS/single-dish dataset with the single-dish only RM gradients. We tentatively show that the difference in beamsize between the datasets can be responsible for this. We interpret the scaled-up RM we find in terms of a simple toy model, and by combining our results with those by Haverkorn et al. (2004) we reconstruct the full 3D magnetic field vector along a number of lines-of-sight. For these lines-of-sight we derive the properties of the magnetic field component perpendicular to the Galactic plane. Comment: accepted for publication in A&A; 16 pages, 9 figures, 2 tables, 1 online figure |
| Databáze: | OpenAIRE |
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