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相关论文: Polarization alignments of radio quasars in JVAS/C…

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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…

天体物理学 · 物理学 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…

天体物理学 · 物理学 2008-11-26 N. Jackson , R. A. Battye , I. W. A. Browne , S. Joshi , T. W. B. Muxlow , P. N. Wilkinson

We present a detailed statistical analysis of the alignment of polarizations of radio sources at high redshift. We use the JVAS/CLASS 8.4-GHz surveys for our study. This study is motivated by the puzzling signal of alignment of…

宇宙学与河外天体物理 · 物理学 2015-03-20 Prabhakar Tiwari , Pankaj Jain

Based on a sample of 355 quasars with significant optical polarization, we found that quasar polarization vectors are not randomly oriented over the sky as naturally expected. The probability that the observed distribution of polarization…

天体物理学 · 物理学 2014-01-22 D. Hutsemekers , A. Payez , R. Cabanac , H. Lamy , D. Sluse , B. Borguet , J. -R. Cudell

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…

天体物理学 · 物理学 2009-10-31 D. Hutsemekers , H. Lamy

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…

宇宙学与河外天体物理 · 物理学 2014-08-13 Richard Shurtleff

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…

天体物理学 · 物理学 2009-11-13 D. Hutsemekers , R. Cabanac , H. Lamy , D. Sluse

The comparison of the orientations of the optical-polarization vectors of quasars that are separated by billions of light-years has led to the discovery that they are aligned instead of pointing in random directions as expected. This…

宇宙学与河外天体物理 · 物理学 2016-04-19 Vincent Pelgrims

We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this unified radio database, we construct radio "color-magnitude-morphology" diagrams and find…

The 355 optically polarized QSOs have redshifts from 0.061 to 3.94 and are spread out over the sky except for a 60 degree band centered on the Galactic Equator. The data we analyze was measured, collected and published by others. Here, we…

宇宙学与河外天体物理 · 物理学 2023-04-20 Richard Shurtleff

Recently, evidence has been presented for the polarization vectors from quasars to preferentially align with the axes of the large quasar groups (LQG) to which they belong. This report was based on observations made at optical wavelengths…

星系天体物理 · 物理学 2016-05-11 Vincent Pelgrims , Damien Hutsemékers

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…

天体物理学 · 物理学 2009-11-13 Simon Johnston , M. Kramer , A. Karastergiou , G. Hobbs , S. Ord , J. Wallman

Polarization measurements are presented for 52 radio-loud QSOs and BL Lac objects. For 9 highly polarized (p >3%) AGN, these are the first published polarization measurements. Of these 9, 7 are highly-polarized QSOs (HPQs), one is a BL Lac…

天体物理学 · 物理学 2009-10-30 Natarajan Visvanathan , Beverley J. Wills , .

A survey measuring quasar polarization vectors has been started in two regions towards the North and South Galactic Poles. Here, We review the discovery of significant correlations of orientations of polarization vectors over huge angular…

天体物理学 · 物理学 2007-05-23 Remi A. Cabanac , Damien Hutsemekers , Dominique Sluse , Herve Lamy

We have measured the optical linear polarization of quasars belonging to Gpc-scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar polarization vectors are either parallel…

星系天体物理 · 物理学 2014-11-19 Damien Hutsemékers , Lorraine Braibant , Vincent Pelgrims , Dominique Sluse

New linear polarization measurements (mainly in the V band) are presented for 203 quasi-stellar objects (QSOs). The sample is made up of 94 QSOs located in the North Galactic Pole (NGP) region and of 109 QSOs in the South Galactic Pole…

天体物理学 · 物理学 2008-11-26 D. Sluse , D. Hutsemekers , H. Lamy , R. Cabanac , H. Quintana

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…

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…

星系天体物理 · 物理学 2018-02-07 Tessa Vernstrom , Bryan Gaensler , Valentina Vacca , Jamie Farnes , Marijke Haverkorn , Shane O'Sullivan

Correlated orientations of quasar optical and radio polarisation, and of radio jets, have been reported on Gpc scales, possibly arising from intrinsic alignment of spin axes. Optical quasar polarisation appears to be preferentially either…

宇宙学与河外天体物理 · 物理学 2022-02-09 Tracey Friday , Roger G. Clowes , Gerard M. Williger

Aims: The ``bright'' High Frequency Peakers (HFPs) sample is a mixture of blazars and intrinsically small and young radio sources. We investigate the polarimetric characteristics of 45 High Frequency Peakers, from the ``bright'' HFP sample,…

天体物理学 · 物理学 2009-11-13 M. Orienti , D. Dallacasa
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