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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

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…

Astrophysics · Physics 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…

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

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…

Astrophysics · Physics 2007-05-23 Remi A. Cabanac , Damien Hutsemekers , Dominique Sluse , Herve Lamy

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 observation of redshift-dependent coherent orientations of quasar polarisation vectors over cosmological distances in some regions of the sky is reviewed. Based on a good-quality sample of 355 measured quasars, this observation seems to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 A. Payez , D. Hutsemekers , J. R. Cudell

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…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Tracey Friday , Roger G. Clowes , Gerard M. Williger

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 studied the distribution of $B_J<20.5$ galaxies from the ROE/NRL COSMOS/UKST catalogue around two samples of $z>0.3$ QSOs with similar redshift distributions. The first sample is formed by 144 radio-loud QSOs from the Parkes…

Astrophysics · Physics 2016-08-30 N. Benitez , E. Martinez-Gonzalez , IFCA

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…

Astrophysics of Galaxies · Physics 2014-11-19 Damien Hutsemékers , Lorraine Braibant , Vincent Pelgrims , Dominique Sluse

A thorough study of QSO-galaxy correlations has been done on a region close to the North Galactic Pole using a complete subsample of the optically selected CFHT/MMT QSO survey and the galaxy catalog of Odewahn and Aldering (1995). Although…

Astrophysics · Physics 2009-10-30 I. Ferreras , N. Benitez , E. Martinez-Gonzalez

We propose a new method to analyse the alignment of optical polarisation vectors from quasars. This method leads to a definition of intrinsic preferred axes and to a determination of the probability $p^{\sigma}$ that the distribution of…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-17 Vincent Pelgrims , Jean-Rene Cudell

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…

Astrophysics · Physics 2009-10-30 Natarajan Visvanathan , Beverley J. Wills , .

Several recent studies show that bright, intermediate and high redshift optically and radio selected QSOs are positively correlated with nearby galaxies on a range of angular scales up to a degree. Obscuration by unevenly distributed…

Astrophysics · Physics 2009-10-31 Liliya L. R. Williams

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…

Astrophysics · Physics 2008-11-26 D. Sluse , D. Hutsemekers , H. Lamy , R. Cabanac , H. Quintana

Two new samples of QSOs have been constructed from recent surveys to test the hypothesis that the redshift distribution of bright QSOs is periodic in $\log(1+z)$. The first of these comprises 57 different redshifts among all known close…

Astrophysics · Physics 2009-10-31 G. Burbidge , W. M. Napier

We investigate correlations between the optical linear polarization position angle and the orientation of the host galaxy/extended emission of Type 1 and Type 2 Radio-Loud (RL) and Radio-Quiet (RQ) quasars. We have used high resolution…

Astrophysics · Physics 2007-10-29 B. Borguet , D. Hutsemékers , G. Letawe , Y. Letawe , P. Magain

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 present new optical circular polarization measurements with typical uncertainties < 0.1% for a sample of 21 quasars. All but two objects have null circular polarization. We use this result to constrain the polarization due to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 D. Hutsemékers , B. Borguet , D. Sluse , R. Cabanac , H. Lamy

We report the discovery of significant linear polarization (p > 1%) in the hyperluminous z=3.87 BALQSO APM~08279+5255. The polarization spectrum is complex, with properties similar to those of other, lower redshift but more highly polarized…

Astrophysics · Physics 2009-10-31 Dean C. Hines , Gary D. Schmidt , Paul S. Smith
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