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Polarization Data (polarization + data)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

X-ray spectroscopy of the intermediate polar PQ Gem

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2002
Cynthia H. James
Abstract Using RXTE and ASCA data, we investigate the roles played by occultation and absorption in the X-ray spin pulse profile of the intermediate polar PQ Gem. From the X-ray light curves and phase-resolved spectroscopy, we find that the intensity variations are the result of a combination of varying degrees of absorption and the accretion regions rotating behind the visible face of the white dwarf. These occultation and absorption effects are consistent with those expected from the accretion structures calculated from optical polarization data. We can reproduce the changes in absorber covering fraction either from geometrical effects, or by considering that the material in the leading edge of the accretion curtain is more finely fragmented than in other parts of the curtain. We determine a white dwarf mass of , 1.2 using the RXTE data. [source]

A circular statistical method for extracting rotation measures

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2001
S. Sarala
We propose a new method for the extraction of rotation measures from spectral polarization data. The method is based on maximum likelihood analysis and takes into account the circular nature of the polarization data. The method is unbiased and statistically more efficient than the standard ,2 procedure. We also find that the method is computationally much more convenient than the standard ,2 procedure if the number of data points is very large. We find that for most sources the method gives results very close to the standard ,2 minimization procedure. We give results for all the cases for which the method gives significantly different results from ,2 minimization. We also make a ,3 fit to the data in order to extract non-Faraday rotation behaviour for those sources for which a large number of data points are available. [source]

Toru, 6-cm polarimetry of the MilkyWay

ASTRONOMISCHE NACHRICHTEN, Issue 5-6 2006
S. Ry
Abstract We present first results of a radio continuum and polarization survey of the Milky Way at 4.7 GHz carried out with the 32-m radio telescope in Toru,. The survey is much less affected by depolarization effects than previous measurements at lower frequencies. This enables the study of magnetic field structure and its interrelations with particular features in the interstellar medium to much larger distances from the Sun. Our preliminary total power map shows a good association of radio features with galactic star-forming regions while the polarization data reveal an increasing coherence of magnetic fields away from the Galaxy's mid-plane. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]