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We develop two algorithms, based on maximum likelihood (ML) inference, for estimating the parameters of polarized radio sources which emit at a single rotation measure (RM), e.g., pulsars. These algorithms incorporate the flux density…

Instrumentation and Methods for Astrophysics · Physics 2017-10-25 D. H. F. M. Schnitzeler , K. J. Lee

Measurements of the polarization of radio emission are subject to a number of depolarization effects such as bandwidth depolarization, which is caused by the averaging effect of a finite channel bandwidth combined with the…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Maxwell A. Fine , Cameron L. Van Eck , Luke Pratley

We study the polarization properties of 22 known rotating radio transients (RRATs) with the 64-m Parkes radio telescope and present the Faraday rotation measures (RMs) for the 17 with linearly polarized flux exceeding the off-pulse noise by…

High precision polarization measurements open new opportunities for the study of the magnetic field structure as traced by polarimetric measurements of the interstellar dust emission. Polarization parameters suffer from bias in the presence…

Astrophysics of Galaxies · Physics 2017-03-15 D. Alina , L. Montier , I. Ristorcelli , J. -P. Bernard , F. Levrier , E. Abdikamalov

We present an analysis of the polarization of compact radio sources from six pointings of the Westerbork Synthesis Radio Telescope (WSRT) at 350 MHz with 35% coverage in lambda^2. After correcting for the off-axis instrumental polarization…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Damon Farnsworth , Lawrence Rudnick , Shea Brown

With the forthcoming release of high precision polarization measurements, such as from the Planck satellite, it becomes critical to evaluate the performance of estimators for the polarization fraction and angle. These two physical…

Instrumentation and Methods for Astrophysics · Physics 2015-02-11 L. Montier , S. Plaszczynski , F. Levrier , M. Tristram , D. Alina , I. Ristorcelli , J. -P. Bernard , V. Guillet

A fully analytic statistical formalism does not yet exist to describe radio-wavelength measurements of linearly polarized intensity that are produced using rotation measure synthesis. In this work we extend the analytic formalism for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Christopher A. Hales , Bryan M. Gaensler , Ray P. Norris , Enno Middelberg

We present a novel Bayesian model and a corresponding robust, probabilistic calibration procedure for the CORSAIR polarimeter that can be applied to other polarimeters. Our calibration procedure combines existing Mueller matrix…

Solar and Stellar Astrophysics · Physics 2026-05-28 Alan Hsu , Jenna Samra , Steven Tomczyk , Maxim Kramar

Faraday rotation measure (RM) synthesis is an important tool to study and analyze galactic and extra-galactic magnetic fields. Since there is a Fourier relation between the Faraday dispersion function and the polarized radio emission, full…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Feng Li , Shea Brown , Tim J. Cornwell , Frank de Hoog

We re-formulate rotation measure (RM) synthesis for data sets with discrete frequency channels and an arbitrary channel response function. The most commonly used version of the formalism by Brentjens & De Bruyn assumes a top-hat response…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 D. H. F. M. Schnitzeler , K. J. Lee

Faraday Rotation Measure (RM) Synthesis, as a method for analyzing multi-channel observations of polarized radio emission to investigate galactic magnetic fields structures, requires the definition of complex polarized intensity in the…

Astrophysics of Galaxies · Physics 2015-05-14 P. Frick , D. Sokoloff , R. Stepanov , R. Beck

The determination of the true source polarization given a set of measurements is complicated by the requirement that the polarization always be positive. This positive bias also hinders construction of upper limits, uncertainties, and…

Astrophysics · Physics 2009-04-15 John E. Vaillancourt

Polarisation amplitude estimation is affected by a positive noise bias, particularly important in regions with low signal-to-noise ratio (SNR). We present a new approach to correct for this bias in the case there is additional information…

Instrumentation and Methods for Astrophysics · Physics 2016-06-29 Matias Vidal , J. P. Leahy , C. Dickinson

A number of polarization estimators have been developed for a variety of astrophysical applications to compensate measurements of linear polarization for a bias contributed by the instrumental noise. Most derivations of the estimators…

High Energy Astrophysical Phenomena · Physics 2025-03-11 M. M. McKinnon

In many polarimetry applications, including observations in the X-ray band, the measurement of a polarization signal can be reduced to the detection and quantification of a deviation from uniformity of a distribution of measured angles. We…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Tod E. Strohmayer , Tim R. Kallman

At the highest levels of pulsar timing precision achieved to date, experiments are limited by noise intrinsic to the pulsar. This stochastic wideband impulse modulated self-noise (SWIMS) limits pulsar timing precision by randomly biasing…

Instrumentation and Methods for Astrophysics · Physics 2013-01-23 Stefan Osłowski , Willem van Straten , Paul Demorest , Matthew Bailes

Using polarization measurements in remote sensing and optical studies allows retrieving more information. We consider relationship between the reflection coefficients of plane and rough surfaces for linearly polarized waves. Certain…

Optics · Physics 2012-12-14 Yu. K. Shestopaloff

With the forthcoming release of high precision polarization measurements, such as from the Planck satellite, the metrology of polarization needs to improve. In particular, it is crucial to take into account full knowledge of the noise…

Instrumentation and Methods for Astrophysics · Physics 2015-02-11 L. Montier , S. Plaszczynski , F. Levrier , M. Tristram , D. Alina , I. Ristorcelli , J. -P. Bernard

We present a new algorithm for fitting and classifying polarized radio sources, which is based on the QU fitting method introduced by O'Sullivan et al. and on our analysis of pulsars. Then we test this algorithm using Monte Carlo…

Instrumentation and Methods for Astrophysics · Physics 2020-06-17 D. H. F. M. Schnitzeler

The new generation of broad-band radio continuum surveys will provide large data sets with polarization information. New algorithms need to be developed to extract reliable catalogs of linearly polarized sources that can be used to…

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