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Recent polarimetric surveys of extragalactic radio sources (ERS) at frequencies \nu>1GHz are reviewed. By exploiting all the most relevant data on the polarized emission of ERS we study the frequency dependence of polarization properties of…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-27 M. Tucci , L. Toffolatti

We describe an experiment to measure calibration sources, the polarization of Cosmic Microwave Background Radiation (CMBR) and the polarization induced on the CMBR from S-Z effects, using a polarimeter, MITOPol, that will be employed at the…

We report the first detection of linearly polarized emission at an observing wavelength of 350 $\mu$m from the radio-loud Active Galactic Nucleus 3C 279. We conducted polarization observations for 3C 279 using the SHARP polarimeter in the…

Radio polarimetry is an invaluable tool to investigate the physical conditions and variability processes in active galactic nuclei (AGN) jets. However, detecting their linear and circular polarization properties is a challenging endeavor…

High Energy Astrophysical Phenomena · Physics 2016-11-30 Ioannis Myserlis , Emmanouil Angelakis , Alex Kraus , Lars Fuhrmann , Vassilis Karamanavis , J. Anton Zensus

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

We describe the POLAMI program for the monitoring of all four Stokes parameters of a sample of bright radio-loud active galactic nuclei with the IRAM 30m telescope at 3.5 and 1.3mm. The program started in October 2006 and accumulated, until…

We present high sensitivity ($\sigma_P \simeq 0.6\,$mJy) polarimetric observations in seven bands, from $2.1$ to $38\,$GHz, of a complete sample of $104$ compact extragalactic radio sources brighter than $200\,$mJy at $20\,$GHz.…

By measuring photoelectron tracks, the gas pixel detectors of the Imaging X-ray Polarimetry Explorer satellite provide estimates of the photon detection location and its electric vector position angle (EVPA). However, imperfections in…

Instrumentation and Methods for Astrophysics · Physics 2024-09-24 Jack T. Dinsmore , Roger W. Romani

The bright polarized synchrotron emission, away from the Galactic plane, originates mostly from filamentary structures. We implement a filament finder algorithm which allows the detection of bright elongated structures in polarized…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 F. A. Martire , A. J. Banday , E. Martínez-González , R. B. Barreiro

Evidence of polarized $\gamma$-ray emission ($>$ 50 keV) from Gamma-Ray Bursts (GRBs) has been accumulated in recent years. Measurements have been reported with levels in the range of 30-80\%, typically with limited statistical…

High Energy Astrophysical Phenomena · Physics 2017-02-22 Mark L. McConnell

A critical challenge in the observation of the redshifted 21-cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-18 C. D. Nunhokee , G. Bernardi , S. A. Kohn , J. E. Aguirre , N. Thyagarajan , J. S. Dillon , G. Foster , T. L. Grobler , J. Z. E. Martinot , A. R. Parsons

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

We present an analysis of the linear polarization of six active galactic nuclei - 0415+379 (3C~111), 0507+179, 0528+134 (OG+134), 0954+658, 1418+546 (OQ+530), and 1637+574 (OS+562). Our targets were monitored from 2007 to 2011 in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 S. Trippe , R. Neri , M. Krips , A. Castro-Carrizo , M. Bremer , V. Pietu , J. M. Winters

A deep radio observation of the A2255 cluster of galaxies has been carried out at 1.4 GHz with the Very Large Array synthesis telescope. Thanks to the excellent (u,v) coverage and sensitivity achieved by our observation, the low brightness…

We present a broadband polarization analysis of 36 discrete polarized radio sources over a very broad, densely-sampled frequency band. Our sample was selected on the basis of polarization behaviour apparent in narrowband archival data at…

High Energy Astrophysical Phenomena · Physics 2016-07-06 C. S. Anderson , B. M. Gaensler , I. J. Feain

We present polarization measurements at 8.4, 22, and 43 GHz made with the VLA of a complete sample of extragalactic sources stronger than 1 Jy in the 5-year WMAP catalogue and with declinations north of -34 degrees. The observations were…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 N. Jackson , I. W. A. Browne , R. A. Battye , D. Gabuzda , A. C. Taylor

Radio sources are often polarized. Accurate measurement of simply the flux density of a radio source requires a basic understanding of polarization and its measurement techniques. We provide an introductory, heuristic discussion of these…

Astrophysics · Physics 2007-05-23 Carl Heiles

Astrophysical sources such as radio halos and relics in galaxy clusters, supernova remnants and radio galaxies have angular sizes from a few to several $10$s of arcminutes. In radio interferometric imaging of such sources, the largest…

Instrumentation and Methods for Astrophysics · Physics 2017-09-13 Deepak Kumar Deo , Ruta Kale

We compare a set of contemporary Galactic magnetic field (GMF) models with polarized synchrotron observations from the S-PASS and C-BASS radio surveys and combine them to create a reconstructed 4.76~GHz full sky map. Pixels that potentially…

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…

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