Browse > Article
http://dx.doi.org/10.5140/JASS.2011.28.4.267

Ricean Bias Correction in Linear Polarization Observation  

Sohn, Bong-Won (Korea Astronomy Observatory, Yonsei University Observatory)
Publication Information
Journal of Astronomy and Space Sciences / v.28, no.4, 2011 , pp. 267-271 More about this Journal
Abstract
I developed an enhanced correction method for Ricean bias which occurs in linear polarization measurement. Two known methods for Ricean bias correction are reviewed. In low signal-to-noise area, the method based on the mode of the equation gives better representation of the fractional polarization. But a caution should be given that the accurate estimation of noise level, i.e. ${\sigma}$ of the polarized flux, is important. The maximum likelihood method is better choice for high signal-to-noise area. I suggest a hybrid method which uses the mode of the equation at the low signal-to-noise area and takes the maximum likelihood method at the high signal-to-noise area. A modified correction coefficient for the mode solution is proposed. The impact on the depolarization measure analysis is discussed.
Keywords
polarization; data analysis; Ricean bias; radio loud active galactic nuclei;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Burn JP, On the depolarization of discrete radio sources by Faraday dispersion, MNRAS, 133, 67 (1966).   DOI
2 Garrington ST, Leahy JP, Conway RG, Laing RA, A systematic asymmetry in the polarization properties of double radio sources with one jet, Natur, 331, 147-149 (1988). http://dx.doi.org/10.1038/331147a0   DOI
3 Killeen NEB, Bicknell GV, Ekers RD, The radio galaxy IC 4296 (PKS 1333 - 33). I. Multifrequency Very Large Array observations, ApJ, 302, 306-336 (1986). http://dx.doi.org/10.1086/163992   DOI
4 Laing RA, Physics of energy transport in extragalatic radio sources, in Proceedings of National Radio Astronomy Observatory Workshop No. 9, Green Bank, WV, 30 Jul-3 Aug, 1984.
5 Laing RA, The sidedness of jets and depolarization in powerful extragalactic radio sources, Nature, 331, 149-151 (1988). http://dx.doi.org/10.1038/331149a0   DOI
6 National Radio Astronomical Observatory, AIPS cookbook (National Radio Astronomical Observatory, Charlottesville, 2011).
7 Simard-Normandin M, Kronberg PP, Button S, The Faraday rotation measures of extragalactic radio sources, ApJS, 45, 97-111 (1981). http://dx.doi.org/10.1086/190709   DOI
8 Vinokur M, Optimisation dans la recherche d'une sinusoide de periode connue en presence de bruit. Application a la radioastronomie, AnAp, 28, 412 (1965).
9 Wardle JFC, Kronberg PP, The linear polarization of quasi-stellar radio sources at 3.71 and 11.1 centimeters, ApJ, 194, 249-255 (1974). http://dx.doi.org/10.1086/153240   DOI