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Related papers: Characterisation of the CAFOS linear spectro-polar…

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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

We have built and tested a compact, low-cost, but very-high-performance astronomical polarimeter based on a continuously rotating half-wave plate and a high-speed imaging detector. The polarimeter is suitable for small telescopes up to ~1 m…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Jeremy Bailey , Daniel V. Cotton , Ain De Horta , Lucyna Kedziora-Chudczer , Om Shastri

Taking advantage of the advances in array detector technology, an imaging polarimeter (IMPOL) has been constructed for measuring linear polarization in the wavelength band from 400-800 nm. It makes use of a Wollaston prism as the analyser…

Astrophysics · Physics 2009-09-15 A. N. Ramaprakash , Ranjan Gupta , A. K. Sen , S. N. Tandon

Precise polarisation measurements of the cosmic microwave background (CMB) require accurate knowledge of the instrument orientation relative to the sky frame used to define the cosmological Stokes parameters. Suitable celestial calibration…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-09 M. H. Abitbol , J. C. Hill , B. R. Johnson

We report the detection of high polarization in the first detailed optical linear polarization measurements on the BL Lac object CGRaBS J0211+1051, which flared in $\gamma$-rays on 2011 January 23 as reported by Fermi. The observations were…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Sunil Chandra , Kiran S Baliyan , Shashikiran Ganesh , Umesh Joshi

We present a study of the linear polarization properties of radio sources within the 10 deg$^2$ Wide Chandra Deep Field South (W-CDFS) in S-band (2-4 GHz). Our W-CDFS image has an angular resolution of 15 arcsec and a 1$\sigma$ RMS in…

Context: Polarimetry is a very powerful tool to uncover various properties of astronomical objects that remain otherwise hidden in standard imaging or spectroscopic observations. However, the reliable measurement of the low polarization…

Instrumentation and Methods for Astrophysics · Physics 2020-02-12 S. González-Gaitán , A. M. Mourão , F. Patat , J. P. Anderson , A. Cikota , K. Wiersema , A. B. Higgins , K. Silva

A high degree of linear polarization measured in the optical emission is an important observational feature of blazars. It provides strong evidence of the presence of relativistic particles and magnetic field ordering in the non-thermal…

High Energy Astrophysical Phenomena · Physics 2025-03-17 K K Singh , A Singh , A Tolamatti , P J Meintjes , K K Yadav

Polarization leakage of foreground synchrotron emission is a critical issue in HI intensity mapping experiments. While the sought-after HI emission is unpolarized, polarized foregrounds such as Galactic and extragalactic synchrotron…

Instrumentation and Methods for Astrophysics · Physics 2016-12-28 Yu-Wei Liao , Tzu-Ching Chang , Cheng-Yu Kuo , Kiyoshi Wesley Masui , Niels Oppermann , Ue-Li Pen , Jeffrey B. Peterson

A telescope polarization model for the SST [Swedish 1-m Solar Telescope] is developed and the parameters of this model are fitted to polarization measurements made with a 1-meter linear polarizer in front of the entrance window. In this…

Instrumentation and Methods for Astrophysics · Physics 2010-10-21 Jakob Selbing

We describe the Fourier Transform Spectrometer (FTS) used for in-field testing of the POLARBEAR receiver, an experiment located in the Atacama Desert of Chile which measures the cosmic microwave background (CMB) polarization. The…

We present the first release of the Calar Alto CAFOS direct imaging data, a project led by the Spanish Virtual Observatory with the goal of enhancing the use of the Calar Alto archive by the astrophysics community. Data Release 1 contains…

Instrumentation and Methods for Astrophysics · Physics 2023-03-29 Miriam Cortés-Contreras , Enrique Solano , Jaime Alonso-Hernández , Nicolás Cardiel , Patricia Cruz , Carlos Rodrigo

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…

We present results from our radio polarimetric study with the upgraded Giant Metrewave Radio Telescope (uGMRT) at Band 4 (550-850 MHz) of 3 blazars: radio-loud quasars 3C390.3, 4C71.07 and BL Lac object 1ES 2344+514. The aim of this study…

Astrophysics of Galaxies · Physics 2022-11-30 Janhavi Baghel , Silpa S. , P. Kharb , B. Sebastian , P. Shastri

Our goal is to test the feasibility to obtain accurate measurements of the continuum polarization from high-resolution spectra using the spectropolarimetric mode of ESPaDOnS. We used the new pipeline OPERA to reduce recent and archived…

Instrumentation and Methods for Astrophysics · Physics 2015-01-14 A. Pereyra , C. V. Rodrigues , E. Martioli

We report inelastic light scattering experiments on CaFe_2As_2 in the temperature range of 4 to 290 K. In in-plane polarizations two Raman-active phonon modes are observed at 189 and 211 cm-1, displaying A_1g and B_1g symmetries,…

Superconductivity · Physics 2009-11-13 K. -Y. Choi , D. Wulferding , P. Lemmens , N. Ni , S. L. Bud'ko , P. C. Canfield

This paper presents a polarization calibration method applied to a microwave polarimeter demonstrator based on a near-infrared (NIR) frequency up-conversion stage that allows both optical correlation and signal detection at a wavelength of…

Instrumentation and Methods for Astrophysics · Physics 2022-10-25 Francisco J. Casas , Patricio Vielva , R. Belen Barreiro , Enrique Martínez-González , G. Pascual-Cisneros

We have studied the implications of high sensitivity polarization measurements of objects from the WMAP point source catalogue made using the VLA at 8.4, 22 and 43 GHz. The fractional polarization of sources is almost independent of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 R. A. Battye , I. W. A. Browne , M. W. Peel , N. J. Jackson , C. Dickinson

The B-Machine Telescope is the culmination of several years of development, construction, characterization and observation. The telescope is a departure from standard polarization chopping of correlation receivers to a half wave plate…

Instrumentation and Methods for Astrophysics · Physics 2013-11-11 Brian D. Williams