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Related papers: Polarization Alignment in JVAS/CLASS flat spectrum…

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We test the hypothesis that the polarization vectors of flat-spectrum radio sources (FSRS) in the JVAS/CLASS 8.4-GHz surveys are randomly oriented on the sky. The sample with robust polarization measurements is made of $4155$ objects and…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-24 Vincent Pelgrims , Damien Hutsemékers

We have used the very large JVAS/CLASS 8.4-GHz surveys of flat-spectrum radio sources to test the hypothesis that there is a systematic alignment of polarization position angle vectors on cosmological scales of the type claimed by…

Astrophysics · Physics 2009-06-23 S. A. Joshi , R. A. Battye , I. W. A. Browne , N. Jackson , T. W. B. Muxlow , P. N. Wilkinson

We have used the very large JVAS/CLASS 8.4-GHz surveys of flat-spectrum radio sources to obtain a large, uniformly observed and calibrated, sample of radio source polarizations. These are useful for many investigations of the properties of…

Astrophysics · Physics 2008-11-26 N. Jackson , R. A. Battye , I. W. A. Browne , S. Joshi , T. W. B. Muxlow , P. N. Wilkinson

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 report on polarimetric observations of 100 pulsars centered on 774 MHz, made using the Green Bank Telescope, presenting their polarization profiles and polarized flux densities and comparing them with previous observations when possible.…

Solar and Stellar Astrophysics · Physics 2009-03-25 J. L. Han , P. B. Demorest , W. van Straten , A. G. Lyne

We introduce several coordinate invariant statistical procedures in order to test for local alignment of polarizations. A large scale alignment of optical polarizations from distant QSOs has recently been observed by \huts and…

Astrophysics · Physics 2009-11-07 Pankaj Jain , Gaurav Narain , S. Sarala

The observed large-scale alignment of polarization angles and galaxy axis have been challenging the fundamental assumption of homogeneity and isotropy in standard cosmology since more than two decades. The intergalactic magnetic field, and…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-07 Prabhakar Tiwari , Pankaj Jain

We report on full-Stokes L-band observations of 98 MeerKAT calibration sources. Linear polarization is detected in 71 objects above a fractional level of 0.2\%. We identify ten sources with strong fractional linear polarization and low…

Astrophysics of Galaxies · Physics 2024-05-24 A. R. Taylor , L. S. Legodi

We have carried out observations at 18.5 GHz with the Australia Telescope Compact Array (ATCA) of 250 out of the 258 Southern extragalactic sources in the complete 5 GHz 1 Jy sample by K\"uhr et al. (1981). In this paper we focus on the…

Astrophysics · Physics 2009-11-10 R. Ricci , I. Prandoni , C. Gruppioni , R. J. Sault , G. De Zotti

We study the alignment of radio galaxies axes using the FIRST catalogue. we impose several cuts in order to select the candidates which are most likely to be free of systematic bias. In our study we primarily focus on testing for alignment…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Mohit Panwar , Prabhakar , Pritpal Kaur Sandhu , Yogesh Wadadekar , Pankaj Jain

Based on a new sample of 355 quasars with significant optical polarization and using complementary statistical methods, we confirm that quasar polarization vectors are not randomly oriented over the sky with a probability often in excess of…

Astrophysics · Physics 2009-11-13 D. Hutsemekers , R. Cabanac , H. Lamy , D. Sluse

We present the largest ever sample of radio polarization properties for $z>4$ sources, with 14 sources having significant polarization detections. Using wideband data from the Karl G. Jansky Very Large Array, we obtained the rest-frame…

Astrophysics of Galaxies · Physics 2018-02-07 Tessa Vernstrom , Bryan Gaensler , Valentina Vacca , Jamie Farnes , Marijke Haverkorn , Shane O'Sullivan

The low-frequency polarisation properties of radio sources are poorly studied, particularly in statistical samples. However, the new generation of low-frequency telescopes, such as the Murchison Widefield Array (MWA; the precursor for the…

We have conducted observations of 22 pulsars at frequencies of 0.7, 1.4 and 3.1 GHz and present their polarization profiles. The observations were carried out for two main purposes. First we compare the orientation of the spin and velocity…

Astrophysics · Physics 2009-11-13 Simon Johnston , M. Kramer , A. Karastergiou , G. Hobbs , S. Ord , J. Wallman

Gamma-ray emitting blazars have been the targets of many recent or ongoing monitoring programmes. The resulting multi-wavelength data archives are ideal for studying the quiescent and variable behaviour of the blazar PKS 2155-304. Here,…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Nikki Pekeur , Russ Taylor , Renée Kraan-Korteweg

We present results from deep, wideband, high spatial and spectral resolution observations of the nearby luminous radio galaxy Cygnus A with the Jansky Very Large Array. The high surface brightness of this source enables detailed…

Astrophysics of Galaxies · Physics 2023-08-10 M. Lerato Sebokolodi , Rick Perley , Jean Eilek , Chris Carilli , Oleg Smirnov , Robert Laing , Eric Greisen , Michael Wise

We present total-intensity and linear-polarization observations made with the Very Large Array at $\lambda$20 and 6 cm of a representative sample of 42 radio galaxies and quasars selected from the Molonglo Complete Sample. The sources have…

Astrophysics · Physics 2009-10-31 C. H. Ishwara-Chandra , D. J. Saikia , V. K. Kapahi , P. J. McCarthy

We present the results of a search for galaxy alignments in 12 galaxy clusters at z>0.5, a statistically complete subset of the very X-ray luminous clusters from the MAssive Cluster Survey (MACS). Using high-quality images taken with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Chao-Ling Hung , Harald Ebeling

In order to verify the existence of coherent orientations of quasars polarization vectors on very large scales, we have obtained new polarization measurements for a sample of quasars located in a given region of the three-dimensional…

Astrophysics · Physics 2009-10-31 D. Hutsemekers , H. Lamy

Various studies have laid claim to finding an alignment of the polarization vectors or radio jets of active galactic nuclei (AGN) over large distances, but these results have proven controversial and so far, there is no clear explanation…

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