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Spectropolarimetry of broad absorption line quasi-stellar objects with the W. M. Keck Telescope is used to put constraints on their nuclear structure. If the continuum polarization is due to electron (or dust) scattering, then the scattered…

Astrophysics · Physics 2007-05-23 P. M. Ogle

The polarization properties of radio sources at very low frequencies (<200 MHz) have not been widely measured, but the new generation of low-frequency radio telescopes, including the Low Frequency Array (LOFAR: a Square Kilometre Array Low…

Compton backscattering polarimetry provides a fast and accurate method to measure the polarization of an electron beam in a storage ring. Since the method is non-destructive, the polarization of the electron beam can be monitored during…

Instrumentation and Detectors · Physics 2007-05-23 I. Passchier , D. W. Higinbotham , C. W. de Jager , B. E. Norum , N. H. Papadakis , N. P. Vodinas

We demonstrate a coherent quantum measurement for the determination of the degree of polarization (DOP). This method allows to measure the DOP in the presence of fast polarization state fluctuations, difficult to achieve with the typically…

Quantum Physics · Physics 2009-11-10 M. Legre , M. Wegmuller , N. Gisin

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…

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

X-ray Polarimetry is almost as old as X-ray Astronomy. Since the first discovery of X-ray sources theoretical analysis suggested that a high degree of linear polarization could be expected due either to the, extremely non thermal, emission…

Photons preferentially Compton scatter perpendicular to the plane of polarisation. This property can be exploited to design instruments to measure the linear polarisation of hard X-rays ($\sim$10 - 100 keV). Photons may undergo two…

Instrumentation and Detectors · Physics 2023-01-25 Ettore Del Monte , Sergio Fabiani , Mark Pearce

New-generation X-ray polarimeters currently under development promise to open a new window in the study of high-energy astrophysical sources. Among them, neutron stars appear particularly suited for polarization measurements. Radiation from…

High Energy Astrophysical Phenomena · Physics 2015-09-24 Roberto Taverna , Roberto Turolla , Denis Gonzalez Caniulef , Silvia Zane , Fabio Muleri , Paolo Soffitta

The CMB polarization is the Everest in the quest to characterize the earliest photons from the Universe. After a long list of ever-decreasing upper limits, a detection of polarization was made in 2002 by the DASI team at ell =~ 500. The…

Instrumentation and Methods for Astrophysics · Physics 2024-11-28 Denis Barkats

In this work we present a revised measurement of the phase-averaged optical polarisation of the Vela pulsar (PSR B0833-45), for which only one value has been published so far (Wagner & Seifert 2000). Our measurement has been obtained…

Astrophysics · Physics 2009-11-13 R. P. Mignani , S. Bagnulo , J. Dyks , G. Lo Curto , A. Slowikowska

Context. Circumstellar disks and self-luminous giant exoplanets or companion brown dwarfs can be characterized through direct-imaging polarimetry at near-infrared wavelengths. SPHERE/IRDIS at the Very Large Telescope has the capabilities to…

The precision physics program of the ILC requires precise knowledge of the state of beam polarisation. In fact the Compton polarimeters intended for the ILC will have to measure the polarisation with error a factor of 2 smaller than the…

Instrumentation and Detectors · Physics 2014-11-20 Christoph Bartels , Anthony Hartin , Christian Helebrant , Daniela Kaefer , Jenny List

Complex field measurements are increasingly becoming the standard for state-of-the-art astronomical instrumentation. Complex field measurements have been used to characterize a suite of ground, airborne, and space-based heterodyne receiver…

Instrumentation and Methods for Astrophysics · Physics 2018-09-25 Kristina K. Davis , Willem Jellema , Stephen J. C. Yates , Christopher E. Groppi , Jochem J. A. Baselmans , Andrey M. Baryshev

In this paper we present an error analysis for polarimetric data obtained with dual-beam instruments. After recalling the basic concepts, we introduce the analytical expressions for the uncertainties of polarization degree and angle. These…

Astrophysics · Physics 2009-11-11 Ferdinando Patat , Martino Romaniello

We analyse the circular polarisation data accumulated in the first 7 years of the POLAMI project introduced in an accompanying paper (Agudo et al.). In the 3mm wavelength band, we acquired more than 2600 observations, and all but one of our…

We benchmark the reliability of the Rotation Measure (RM) synthesis algorithm using the 1005 Centaurus A field sources of Feain et al. (2009). The RM synthesis solutions are compared with estimates of the polarization parameters using…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 J. -P. Macquart , R. D. Ekers , I. Feain , M. Johnston-Hollitt

Radio polarimetry at decimetre wavelengths is the principal source of information on the Galactic magnetic field. The diffuse polarized emission is strongly influenced by Faraday rotation in the magneto-ionic medium and rotation measure is…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 M. Wolleben , T. L. Landecker , G. J. Hovey , R. Messing , O. S. Davison , N. L. House , K. H. M. S. Somaratne , I. Tashev

We developed a polarization modulation unit (PMU) to rotate a waveplate continuously in order to observe solar magnetic fields by spectropolarimetry. The non-uniformity of the PMU rotation may cause errors in the measurement of the degree…

Instrumentation and Methods for Astrophysics · Physics 2015-09-25 Shin-nosuke Ishikawa , Toshifumi Shimizu , Ryouhei Kano , Takamasa Bando , Ryohko Ishikawa , Gabriel Giono , Saku Tsuneta , Satoshi Nakayama , Takao Tajima

Modern dual-polarization receivers allow a radio telescope to characterize the full polarization state of incoming insterstellar radio waves. Many astronomers incorrectly consider a polarimeter to be the "backend" of the telescope. We go to…

Instrumentation and Methods for Astrophysics · Physics 2021-10-13 Timothy Robishaw , Carl Heiles
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