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Aims - We report new Very Large Array polarimetric observations of Compact Steep-Spectrum (CSS) sources at 8.4, 15, and 23GHz. Methods - Using multi-frequency VLA observations we have derived sub-arcsecond resolution images of the total…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 F. Mantovani , A. Rossetti , W. Junor , D. J. Saikia , C. J. Salter

Taking into account noise from intrinsic ellipticities of source galaxies, in this paper, we study the peak statistics in weak-lensing convergence maps around clusters of galaxies and beyond. We emphasize how the noise peak statistics is…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Zuhui Fan , Huanyuan Shan , Jiayi Liu

We report the first detection of X-ray polarization in the horizontal branch for GX 340+0 as obtained by Imaging X-ray Polarimetry Explorer (IXPE). A polarization degree of 4.3%$\pm$0.3% is obtained. This value is in agreement with the…

High Energy Astrophysical Phenomena · Physics 2024-11-21 Fabio La Monaca , Alessandro Di Marco , Renee M. Ludlam , Anna Bobrikova , Juri Poutanen , Songwei Li , Fei Xie

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

In strong gravitational lensing, the multiple images we see correspond to light rays that leave the source in slightly different directions. If the source emission is anisotropic, the images may differ from conventional lensing predictions…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Rosalba Perna , Charles R. Keeton

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 estimate the amplitude of the source-lens clustering bias and of the intrinsic-alignment bias of weak lensing estimators of the two-point and three-point convergence and cosmic-shear correlation functions. We use a linear galaxy bias…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-17 Patrick Valageas

The detection of polarized sources in the WMAP 5-year data is a very difficult task. The maps are dominated by instrumental noise and only a handful of sources show up as clear peaks in the Q and U maps. Optimal linear filters applied at…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 M. Lopez-Caniego , M. Massardi , J. Gonzalez-Nuevo , L. Lanz , D. Herranz , G. De Zotti , J. L. Sanz , F. Argueso

Our earlier work [J. Opt. 19. (2017) 0905603] showed that, in contrast to the four parameters of the traditional Stokes vector description of the statistics of the partially polarized light, the complete second-order statistics of the…

Optics · Physics 2023-03-07 Mikhail Charnotskii

The measurement of radio polarization may be regarded as a three-dimensional statistical problem because the large photon densities at radio wavelengths allow the simultaneous detection of the three Stokes parameters which completely…

Astrophysics · Physics 2009-11-07 Mark M. McKinnon

We have derived the relationship between polarization and intensity fluctuations due to point sources. In the case of a Poisson distribution of a population with uniform evolution properties and constant polarization degree, polarization…

Astrophysics · Physics 2009-10-31 G. De Zotti , C. Gruppioni , P. Ciliegi , C. Burigana , L. Danese

We reassess the estimate of the cross-correlation of the spatial distribution of the NRAO VLA Sky Survey (NVSS) radio sources with that of Cosmic Microwave Background (CMB) anisotropies from the Wilkinson Microwave Anisotropy Probe (WMAP).…

Astrophysics · Physics 2009-06-23 A. Raccanelli , A. Bonaldi , M. Negrello , S. Matarrese , G. Tormen , G. De Zotti

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…

Near-infrared polarimetry of point sources reveals the presence of a toroidal magnetic field in the central 20' x 20' region of our Galaxy. Comparing the Stokes parameters between high extinction stars and relatively low extinction ones, we…

We present polarisation profiles for 48 southern pulsars observed with the new 10-cm receiver at the Parkes telescope. We have exploited the low system temperature and high bandwidth of the receiver to obtain profiles which have good signal…

Astrophysics · Physics 2009-11-10 A. Karastergiou , S. Johnston , R. N. Manchester

Source enumeration, the task of estimating the number of sources from the signal received by the array of antennas, is a critical problem in array signal processing. Numerous methods have been proposed to estimate the number of sources…

Signal Processing · Electrical Eng. & Systems 2025-07-03 Gokularam Muthukrishnan , Siva Shanmugam , Sheetal Kalyani

As is known, resonant scattering can distort the surface-brightness profiles of clusters of galaxies in X-ray lines. We demonstrate that the scattered line emission should be polarized and possibly detectable with near-future X-ray…

Astrophysics · Physics 2009-11-07 S. Sazonov , E. Churazov , R. Sunyaev

We present 2micron polarization measurements of positions in the BN region of the Orion Molecular Cloud (OMC-1) made with NICMOS Camera 2 (0.2'' resolution) on HST. Our results are as follows: BN is sim 29% polarized by dichroic absorption…

We study the angular clustering of point sources in The GMRT (Giant Meter Wave Telescope) Sky Survey (TGSS). The survey at 150 MHz with delta > -53.5 degrees has a sky coverage of 3.6 pi steradians, i.e., 90% of the whole sky. We created…

Astrophysics of Galaxies · Physics 2019-06-04 Sandeep Rana , J. S. Bagla

The S-band Polarisation All Sky Survey (SPASS/ATCA) rotation measure (RM) catalogue is the largest broadband RM catalogue to date, increasing the RM density in the sparse southern sky. Through analysis of this catalogue, we report a…

Astrophysics of Galaxies · Physics 2024-06-05 S. Ranchod , S. A. Mao , R. Deane , S. S. Sridhar , A. Damas-Segovia , J. D. Livingston , Y. K. Ma