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Related papers: Polarization analysis of the VLTI and GRAVITY

200 papers

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

The goals of this work are to provide NIR polarimetry of the stellar sources in the central pc at the resolution of an 8m telescope for the first time, along with new insights into the nature of the known bright bow-shock sources. We use AO…

Astrophysics of Galaxies · Physics 2015-05-28 Rainer M. Buchholz , Gunther Witzel , Rainer Schödel , Andreas Eckart , Markus Bremer , Koraljka Muzic

Quantifying the optical chirality of a sample requires the precise measurement of the rotation of the plane of linear polarisation of the transmitted light. Central to this notion is that the sample needs to be exposed to light of a defined…

Quantum Physics · Physics 2022-08-18 S. Restuccia , G. M. Gibson , L. Cronin , M. J. Padgett

The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat consists of an array of a large number of pixellated CZT detectors capable of measuring the polarization of incident hard X-rays. The polarization measurement capability of CZTI for…

Radio interferometers can measure the full polarization state of incoming waves by cross--correlating all combinations of two orthogonal polarizations at each antenna. The independent sets of electronics used to detect the two polarization…

Instrumentation and Methods for Astrophysics · Physics 2012-05-18 W. D. Cotton

The GRAVITY instrument has been commissioned on the VLTI during 2016 and is now available to the astronomical community. It is the first optical interferometer capable of observing sources as faint as magnitude 19 in K-band. This is…

Measuring the polarization of the prompt gamma-ray emission from GRBs can significantly improve our understanding of both the GRB emission mechanisms, as well as the underlying engine driving the explosion. We searched for polarization in…

Astrophysics · Physics 2015-06-24 E. Kalemci , S. E. Boggs , C. Kouveliotou , M. Finger , M. G. Baring

Polarization-resolved near-infrared imaging adds a useful optical contrast mechanism to eye tracking by measuring the polarization state of light reflected by ocular tissues in addition to its intensity. In this paper we demonstrate how…

We present the proposal for the infrared adaptive optics (AO) assisted, two-object, high-throughput, multiple-beam-combiner GRAVITY for the VLTI. This instrument will be optimized for phase-referenced interferometric imaging and…

Astrophysics · Physics 2007-05-23 F. Eisenhauer , G. Perrin , S. Rabien , A. Eckart , P. Lena , R. Genzel , R. Abuter , T. Paumard , W. Brandner

Although not designed primarily as a polarimeter, the \textit{Fermi}-Large Area Telescope (LAT) has the potential to detect high degrees of linear polarization from some of the brightest gamma-ray sources. To achieve the needed accuracy in…

Instrumentation and Methods for Astrophysics · Physics 2019-08-14 Matteo Giomi , Rolf Bühler , Carmelo Sgrò , Francesco Longo , William Atwood

TRIUMF experiment E497 is a study of parity violation in pp scattering at an energy where the leading term in the analyzing power is expected to vanish, thus measuring a unique combination of weak-interaction flavour conserving terms. It is…

Instrumentation and Detectors · Physics 2009-11-06 A. R. Berdoz

Existing depth sensors are imperfect and may provide inaccurate depth values in challenging scenarios, such as in the presence of transparent or reflective objects. In this work, we present a general framework that leverages polarization…

Computer Vision and Pattern Recognition · Computer Science 2024-04-09 Kei Ikemura , Yiming Huang , Felix Heide , Zhaoxiang Zhang , Qifeng Chen , Chenyang Lei

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 explore the signatures of quintessence and modified gravity theories in the relativistic description of galaxy clustering within a parametrized post-Friedmann framework. For this purpose, we develop a calibration method to consistently…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-29 Lucas Lombriser , Jaiyul Yoo , Kazuya Koyama

Polarimetric data provide key insights into infrared emission mechanisms in the inner disks of YSOs and the details of dust formation around AGB stars. While polarization measurements are well-established in radio interferometry, they…

Instrumentation and Methods for Astrophysics · Physics 2025-09-15 Linling Shuai , John D. Monnier , Benjamin R. Setterholm , Stefan Kraus , Narsireddy Anugu , Tyler Gardner , Jean-Baptiste Le Bouquin , Gail H. Schaefer

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

Polarization information of the light can provide rich cues for computer vision and scene understanding tasks, such as the type of material, pose, and shape of the objects. With the advent of new and cheap polarimetric sensors, this imaging…

Computer Vision and Pattern Recognition · Computer Science 2024-01-03 Joaquin Rodriguez , Lew-Fock-Chong Lew-Yan-Voon , Renato Martins , Olivier Morel

The geometric phase is usually treated as a quantity modulo 2\pi, a convention carried over from early work on the subject. The results of a series of optical interference experiments involving polarization of light, done by the present…

Optics · Physics 2015-06-26 Rajendra Bhandari

We demonstrate that polarimetric interferometry can be used to extract precise spatial information about compact polarized flares of Sgr A*. We show that, for a faint dynamical component, a single interferometric baseline suffices to…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Michael D. Johnson , Vincent L. Fish , Sheperd S. Doeleman , Avery E. Broderick , John F. C. Wardle , Daniel P. Marrone

The VLTI instrument GRAVITY combines the beams from four telescopes and provides phase-referenced imaging as well as precision-astrometry of order 10 microarcseconds by observing two celestial objects in dual-field mode. Their angular…