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Related papers: Biases in the polarization position angles in the …

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[abridged] We investigate the effects of various AGN scattering region geometries on the polarized flux. We introduce a new, publicly available Monte Carlo radiative transfer code, Stokes, which models polarization induced by scattering off…

Astrophysics · Physics 2011-01-31 Rene W. Goosmann , C. Martin Gaskell

Using UMRAO centimeter-band total flux density and linear polarization monitoring observations of the complete Pearson-Readhead extragalactic source sample obtained between August 1984 and March 2001, we identify the range of variability in…

Astrophysics · Physics 2009-11-07 M. F. Aller , H. D. Aller , P. A. Hughes

Much interest has been generated recently by the ongoing MACHO, EROS and OGLE projects to identify gravitationally lensed stars from the Large Magellanic Cloud and Galactic bulge, and the positive identification of several events (Alcock et…

Astrophysics · Physics 2007-05-23 J. F. L. Simmons , J. P. Willis , A. Newsam

Recent detailed simulations have shown that an insufficiently accurate characterization of the contamination of unresolved polarized extragalactic sources can seriously bias measurements of the primordial cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-10 T. Trombetti , C. Burigana , G. De Zotti , V. Galluzzi , M. Massardi

Magnetograms from the Vector SpectroMagnetograph (VSM) of the Synoptic Optical Long-term Investigations of the Sun (SOLIS) project are utilized to study the latitude distribution of magnetic flux elements as a function of latitude in the…

Astrophysics · Physics 2008-01-03 N. -E. Raouafi , J. W. Harvey , C. J. Henney

We collected optical and near IR linear polarization data obtained over 20--30 years for a sample of 51 blazars. For each object, we calculated the probability that the distribution of position angles was isotropic. The distribution of…

Astrophysics · Physics 2007-05-23 Michael J. Yuan , Hien Tran , Beverley Wills , D. Wills

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

Many recent studies have demonstrated that scaling arguments, such as the so-called hierarchical {\em ansatz}, are extremely useful in understanding the statistical properties of weak gravitational lensing. This is especially true on small…

Astrophysics · Physics 2009-10-31 Dipak Munshi , Peter Coles

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

We use the Illustris-TNG simulation to investigate the anisotropic distribution of subhalos in/around dark matter halo pairs. We measure the position angle ($\theta$) of each subhalo by the angle between the line connecting it to the…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 Qinglin Ma , Cheng Li , Yanhan Guo

We present an overview of unbiased studies of diffuse extragalactic radio sources. We use a previously developed filtering technique to remove compact sources from large surveys such as WENSS, WISH, and NVSS and examine the residual diffuse…

Astrophysics · Physics 2009-11-11 Lawrence Rudnick , Kisha M. Delain , Jeffrey A. Lemmerman

We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The nuclear sources seen in direct HST images in these galaxies are found to be highly…

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 analyse the distribution of position angles of 1 million galaxies from the Hyperleda catalogue, a sample that presents the galaxies coordinates in the celestial sphere, information that allows us to look for a possible privileged…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-08 R. S. Menezes , C. Pigozzo , S. Carneiro

We estimate the bias on weak lensing mass measurements of shear-selected galaxy cluster samples. The mass bias is expected to be significant because constructions of cluster samples from peaks in weak lensing mass maps and measurements of…

Astrophysics of Galaxies · Physics 2020-03-25 Kai-Feng Chen , Masamune Oguri , Yen-Ting Lin , Satoshi Miyazaki

We develop two algorithms, based on maximum likelihood (ML) inference, for estimating the parameters of polarized radio sources which emit at a single rotation measure (RM), e.g., pulsars. These algorithms incorporate the flux density…

Instrumentation and Methods for Astrophysics · Physics 2017-10-25 D. H. F. M. Schnitzeler , K. J. Lee

In Loeb & Rybicki (1999; paper I) it was shown that before reionization, the scattering of \lya photons from a cosmological source might lead to a fairly compact ($\sim 15''$) \lya halo around the source. Observations of such halos could…

Astrophysics · Physics 2009-10-31 George B. Rybicki , Abraham Loeb

Spatial intensity moments computed on images can be used as a probe of the centroid, size, and orientation of pixelized sources such as stars and galaxies. However, all measurements made on images suffer from errors due to undersampling and…

Instrumentation and Methods for Astrophysics · Physics 2020-12-11 Andrew K. Bradshaw

We present the statistical evaluation of a count rate and area limited complete sample of the ROSAT All-Sky Survey (RASS) comprising 674 sources. The RASS sources are located in six study areas outside the galactic plane (|b^II| >= 20 deg)…