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Gaseous X-ray polarimetry refers to a class of detectors used for measuring the polarization of soft X-rays. The systematic effects of such detectors introduce residual modulation, leading to systematic biases in the polarization detection…

Instrumentation and Methods for Astrophysics · Physics 2024-07-22 Difan Yi , Qian Liu , Hongbang Liu , Fei Xie , Huanbo Feng , Zuke Feng , Jin Li , Enwei Liang , Yangheng Zheng

A primordial degree of circular polarization of the Cosmic Microwave Background is not observationally excluded. The hypothesis of primordial dichroism can be quantitatively falsified if the plasma is magnetized prior to photon decoupling…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Massimo Giovannini

Spatially resolved (sub)millimeter polarization has been detected by ALMA in an increasing number of disks around young stellar objects. The majority of the observations show polarization patterns that are consistent with self-scattering,…

Solar and Stellar Astrophysics · Physics 2019-09-19 Haifeng Yang , Zhi-Yun Li

The investigation of polarized light of protoplanetary disks is key for constraining the dust properties, disk morphology and embedded magnetic fields. However, different polarization mechanisms and the diversity of dust grain shapes and…

Solar and Stellar Astrophysics · Physics 2019-07-17 Robert Brunngräber , Sebastian Wolf

Measuring the alignment of polarized radio sources requires comparing vectors at different locations on the sky, i.e. on a sphere. A test of alignment is derived herein. While both large scale and coordinate independent, the test avoids the…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-13 Richard Shurtleff

Several on-going and future experiments use a Stokes polarimeter (i.e. a rotating wave plate followed by a steady polarizer and by an unpolarized detector) to measure the small polarized component of the Cosmic Microwave Background. The…

Instrumentation and Methods for Astrophysics · Physics 2010-06-17 Maria Salatino , Paolo de Bernardis

State-of-the-art polarimeter calibration is reviewed. Producing many quasi-random polarization states and moving/bending a fiber without changing power allows finding a polarimeter calibration where the degree-of-polarization reaches unity…

Optics · Physics 2022-07-05 Reinhold Noe , Benjamin Koch

We report here the discovery of a significant source of systematic error in the rotation measure determinations of pulsars. Conventional analysis of high sensitivity polarimetric observations of PSR B2016+28 display variation of the…

Astrophysics · Physics 2009-11-10 R. Ramachandran , D. C. Backer , J. M. Rankin , J. M. Weisberg , K. E. Devine

Aims. This research note presents a full analysis of the CAFOS polarimeter mounted at the Calar Alto 2.2m telescope. It also provides future users of this mode with all necessary information to properly correct for instrumental effects in…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 F. Patat , S. Taubenberger

Foreground mitigation is critical to all next-generation radio interferometers that target cosmology using the redshifted neutral hydrogen 21 cm emission line. Attempts to remove this foreground emission have led to new analysis techniques…

Instrumentation and Methods for Astrophysics · Physics 2022-11-22 Kalyani Bhopi , Will Tyndall , Pranav Sanghavi , Kevin Bandura , Laura Newburgh , Jason Gallicchio

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

Context: Radio interferometers measure frequency components of the sky brightness, modulated by the gains of the individual radio antennas. Due to atmospheric turbulence and variations in the operational conditions of the antennas these…

Instrumentation and Methods for Astrophysics · Physics 2023-10-25 Jakob Roth , Philipp Arras , Martin Reinecke , Richard A. Perley , Rüdiger Westermann , Torsten A. Enßlin

A tunable, polarization sensitive microwave filter based on a reconfigurable dual-layered two-dimensional metallic photonic crystal is presented. The filter consists of a metallic plate with periodic holes and metal pillars which are…

Applied Physics · Physics 2024-11-04 Sanaz Zarei

Sizable hyperpolarisation, i.e. an imbalance of the occupation numbers of nuclear spins in a sample deviating from thermal equilibrium, is needed in various fields of science. For example, hyperpolarised tracers are utilised in magnetic…

Linear (spectro) polarimetry is usually performed using separate photon flux measurements after spatial or temporal polarization modulation. Such classical polarimeters are limited in sensitivity and accuracy by systematic effects and…

Optics · Physics 2010-05-28 Frans Snik , Theodora Karalidi , Christoph U. Keller

The NRAO VLA Sky Survey (NVSS) Rotation Measure (RM) catalogue has enabled numerous studies in cosmic magnetism, and will continue being a unique dataset complementing future polarisation surveys. Robust comparisons with these new surveys…

Astrophysics of Galaxies · Physics 2019-05-22 Yik Ki Ma , S. A. Mao , Jeroen Stil , Aritra Basu , Jennifer West , Carl Heiles , Alex S. Hill , S. K. Betti

We present polarisation profiles for 48 southern pulsars observed with the new 10-cm receiver at the Parkes telescope. We have exploited the low system temperature and high bandwidth of the receiver to obtain profiles which have good signal…

Astrophysics · Physics 2009-11-10 A. Karastergiou , S. Johnston , R. N. Manchester

$\textit{Aims.}$ We present a case study to demonstrate the potential of multi-wavelength polarization measurements. The aim is to investigate the effects that dichroic polarization and thermal re-emission have on tracing the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Reissl , S. Wolf , D. Seifried

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
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