Astron. Astrophys. 334, 571-584 (1998)

On the high frequency polarization of pulsar radio emission

A.  von Hoensbroech ¹, J.  Kijak ^{2, 1} and A.  Krawczyk <sup>2, 1

1</sup> Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
² The Astronomical Centre of Zielona Góra, Lubuska 2, PL-65 265 Zielona Góra, Poland

Received 7 November 1997 / Accepted 27 February 1998

Abstract

We have analyzed the polarization properties of pulsars at an observing frequency of 4.9 GHz. Together with low frequency data, we are able to trace polarization profiles over more than three octaves into an interesting frequency regime. At those high frequencies the polarization properties often undergo important changes such as significant depolarization. A detailed analysis allowed us to identify parameters, which regulate those changes. A significant correlation was found between the integrated degree of polarization and the loss of rotational energy .

The data were also used to review the widely established pulsar profile classification scheme of core- and cone-type beams.

We have discovered the existence of pulsars which show a strongly increasing degree of circular polarization towards high frequencies.

Previously unpublished average polarization profiles, recorded at the 100m Effelsberg radio telescope, are presented for 32 radio pulsars at 4.9 GHz. The data were used to derive polarimetric parameters and emission heights.

Key words: polarization radiation mechanisms: non-thermal radiative transfer pulsars: general pulsars: individual: PSR B0144+59; PSR B0355+54

Send offprint requests to: A.  von Hoensbroech, (avh@mpifr-bonn.mpg.de)

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
• 3. Results
  • 3.1. Interesting individual objects
    • 3.1.1. Interpulse: B1702-19
    • 3.1.2. Wide profiles: B1800-21, B1823-13 and B1831-04
    • 3.1.3. High circular polarization: B0144+59, B1737-30 and B1913+10
  • 3.2. Geometry and emission altitudes
• 4. Discussion
  • 4.1. Typical polarimetric types of pulsars
    • 4.1.1. 0355+54-Type
    • 4.1.2. 0525+21-Type
    • 4.1.3. 1800-21-Type
    • 4.1.4. 0144+59-Type
  • 4.2. Correlations between polarization and other pulsar parameters
  • 4.3. Frequency development of circular polarization
• 5. Summary and conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: May 15, 1998

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