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Related papers: Alignment of quasar polarizations with large-scale…

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We report 87 previously unpublished optical linear polarization measurements of 86 quasars obtained in May and October 2008, and from April to July 2015 with the Focal Reducer and low-dispersion Spectrographs FORS1 and FORS2 attached to the…

Astrophysics of Galaxies · Physics 2018-11-28 D. Hutsemékers , B. Borguet , D. Sluse , V. Pelgrims

We have considered polar ring galaxy candidates, the images of which can be found in the SDSS. The sample of 78 galaxies includes the most reliable candidates from the SPRC and PRC catalogs, some of which already have kinematic…

Astrophysics of Galaxies · Physics 2015-06-17 K. I. Smirnova , A. V. Moiseev

We investigate the distribution of companion galaxies around quasars using {\em Hubble Space Telescope} ({\em HST}) Advanced Camera for Surveys Wide Field Camera (ACS/WFC) archival images. Our master sample contains 532 quasars which have…

Astrophysics of Galaxies · Physics 2019-10-09 Minghao Yue , Xiaohui Fan , Jan-Torge Schindler , Ian D. McGreer , Yun-Hsin Huang

Anticipating new spectroscopic studies of quasar companions, we calculate expected emission line spectra for the companion galaxies. Under the assumption of isotropic photoionizing radiation, we predict equivalent widths for Halpha, Hbeta,…

Astrophysics · Physics 2009-10-30 Oleg Y. Gnedin

We performed the check of supposition about the possibility of manifestation of the previously observed phenomenon of central symmetry of the celestial sphere through existence of the opposite quasars. We discovered the existence of some…

General Physics · Physics 2013-01-17 Iurii Kudriavtcev

Observations with the Wide-Field Camera of the Hubble Space Telescope are presented for a representative sample of 20 intrinsically luminous quasars with redshifts smaller than 0.30. These observations show that luminous quasars occur in…

Astrophysics · Physics 2011-07-18 John N. Bahcall , Sofia Kirhakos , David H. Saxe , Donald P. Schneider

Recently, it was shown, that the absence of circular polarization of visible light from quasars, severely constrains the interpretation of axion like particles (ALPs) as a solution for the generation of the linear polarization. Furthermore,…

High Energy Physics - Phenomenology · Physics 2016-03-16 Ki-Young Choi , Subhayan Mandal , Chang Sub Shin

We study the dependence of the number density and properties of quasars on the background galaxy density using the currently largest spectroscopic datasets of quasars and galaxies. We construct a galaxy number density field smoothed over…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Hyunmi Song , Changbom Park , Heidi Lietzen , Maret Einasto

We show that the parameter space of axion-like particles can be severly constrained using high-precision measurements of quasar polarisations. Robust limits are derived from the measured bounds on optical circular polarisation and from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-09 A. Payez , J. R. Cudell , D. Hutsemékers

We report observations of the linear polarization of a sample of 49 nearby bright stars measured to sensitivities of between ~1 and 4 x 10^-6. The majority of stars in the sample show measurable polarization, but most polarizations are…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jeremy Bailey , P. W. Lucas , J. H. Hough

Pulsar polarization profiles are critical for understanding their magnetospheric structures and radiation mechanisms. We present polarization profile measurements for 25 pulsars in globular clusters (GCs) from the observation of the…

High Energy Astrophysical Phenomena · Physics 2025-01-08 Tong Liu , Lin Wang , Zhichen Pan

We present polarisation observations of five pulsars whose profiles exhibit two distinct emission regions separated by close to 180 degrees of longitude. We fitted the position angle of the linear polarisation using the rotating vector…

Solar and Stellar Astrophysics · Physics 2015-05-14 M. J. Keith , S. Johnston , M. Kramer , P. Weltevrede

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,…

Astrophysics · Physics 2009-11-13 M. Orienti , D. Dallacasa

We have investigated the spatial distribution of quasars and its relationship with redshift by using the two-point correlation function, the variance of cell counts and the conditional density as a function of redshift. By comparing our…

Astrophysics · Physics 2007-05-23 P. Andreani , S. Cristiani , F. La Franca

We present strong observational evidence for a relationship between the direction of a pulsar's motion and its rotation axis. We show carefully calibrated polarization data for 25 pulsars, 20 of which display linearly polarized emission…

Astrophysics · Physics 2009-11-13 Simon Johnston , G. Hobbs , S. Vigeland , M. Kramer , J. M. Weisberg , A. G. Lyne

We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of $g<20.85$ and proper transverse separations of $\sim 25\,h^{-1}$\,kpc. Our sample of…

Astrophysics of Galaxies · Physics 2017-04-12 S. Eftekharzadeh , A. D. Myers , J. F. Hennawi , S. G. Djorgovski , G. T. Richards , A. A. Mahabal , M. J. Graham

The evolution of quasar clustering is investigated with a new sample of 388 quasars with 0.3<z<=2.2, B<=20.5 and Mb<-23, selected over an area of 24.6 sq. deg. in the South Galactic Pole. Assuming a two-point correlation function of the…

Astrophysics · Physics 2009-10-30 Fabio La Franca , Paola Andreani , Stefano Cristiani

Gigaparsec scale alignments of the quasar optical polarization vectors have been proven to be robust against a scenario of contamination by the Galactic interstellar medium (ISM). This claim has been established by means of optical…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-13 Vincent Pelgrims

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

We present polarization images with the Karl G. Jansky Very Large Array (VLA) in A and B-array configurations at 6 GHz of 7 radio-loud (RL) quasars and 8 BL Lac objects belonging to the Palomar-Green (PG) `blazar' sample. This completes our…

Astrophysics of Galaxies · Physics 2024-11-12 Janhavi Baghel , P. Kharb , T. Hovatta , Luis C. Ho , C. Harrison , E. Lindfors , Silpa S. , S. Gulati