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Related papers: Polarization in Low Frequency Radio Astronomy

200 papers

In this paper, using the database of the university of Michigan Radio Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio frequencies, we studied the polarization properties for 47 BL Lacertae objects(38 radio…

Low-frequency polarisation observations of pulsars, facilitated by next-generation radio telescopes, provide powerful probes of astrophysical plasmas that span many orders of magnitude in magnetic field strength and scale: from pulsar…

High Energy Astrophysical Phenomena · Physics 2018-08-22 C. Sobey , the LOFAR , MWA collaborations

Microwave background polarization, though presently undetected, is a fundamental prediction of any viable cosmological model. These lectures review the theoretical description of polarization, its physical interpretation, and potentially…

Astrophysics · Physics 2011-04-15 Arthur Kosowsky

Vortex electrons, - freely propagating electrons whose wavefunction has helical wavefronts, - could become a novel tool in the physics of electromagnetic radiation. They carry a non-zero intrinsic orbital angular momentum (OAM) $\ell$ with…

Optics · Physics 2013-11-13 Igor P. Ivanov , Dmitry V. Karlovets

The Helmholtz equation in one dimension, which describes the propagation of electromagnetic waves in effectively one-dimensional systems, is equivalent to the time-independent Schr\"odinger equation. The fact that the potential term…

Classical Physics · Physics 2021-09-15 Farhang Loran , Ali Mostafazadeh

Kostelecky and Mewes have recently shown that sensitive constraints can be placed on some aspects of Lorentz symmetry violation using certain astronomical data on high-redshift sources. Here, I introduce that data in its astronomical…

High Energy Physics - Phenomenology · Physics 2017-08-23 Robert Antonucci

In laser gravitational waves detectors optical loss restricts sensitivity. We discuss polarization scattering as one more possible mechanism of optical losses. Circulated inside interferometer light is polarized and after reflection its…

Instrumentation and Methods for Astrophysics · Physics 2020-02-20 Sergey P. Vyatchanin

A large peculiar velocity of the intergalactic medium produces a Doppler shift of the cosmic microwave background with a frequency-dependent quadrupole term. This quadrupole will act as a source for polarization of the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-20 Elinore Roebber , Gilbert Holder

X-ray polarimetry is now providing a new way to look at the high energy sky. The addition of two observables, polarization fraction and angle, reveals crucial new information on the structure of accretion flows and magnetic fields in…

High Energy Astrophysical Phenomena · Physics 2026-05-08 Philip Kaaret , Brian D. Ramsey

We present observations and analysis of the polarized radio emission from the nearby radio galaxy Fornax A over 1.28--3.1 GHz, using data from the Australia Telescope Compact Array (ATCA). In this, the first of two associated papers, we use…

High Energy Astrophysical Phenomena · Physics 2018-03-21 C. S. Anderson , B. M. Gaensler , G. H. Heald , S. P. O'Sullivan , J. F. Kaczmarek , I. J. Feain

Radio emission from magnetars provides a unique probe of the relativistic, magnetized plasma within the near-field environment of these ultra-magnetic neutron stars. The transmitted waves can undergo birefringent and dispersive propagation…

Light from any physical source diffracts over space, as spherical wavefronts grow and energy density is spread out. Diffractive effects pose fundamental limits to light-based technologies, including communications, spectroscopy, and…

The relative population of the fine structure sublevels of an atom's ground state is affected by radiative transitions induced by an anisotropic radiation flux. This causes the alignment of atomic angular momentum. In terms of observational…

Astrophysics · Physics 2008-11-26 Huirong Yan , A. Lazarian

We study a conspicuous ring-like structure with a radius of about 1.4 degrees which was observed with the Westerbork Synthesis Radio Telescope (WSRT) at 5 frequencies around 350 MHz. This ring is very prominent in Stokes Q and U, and less…

Astrophysics · Physics 2009-11-07 M. Haverkorn , P. Katgert , A. G. de Bruyn

There is an ongoing debate about the origin and even the very existence of a high degree of linear polarization of some chromospheric spectral lines observed in solar flares. The standard explanation of these measurements is in terms of the…

Solar and Stellar Astrophysics · Physics 2015-06-17 Jiri Stepan , Petr Heinzel

Polarization is one of the fundamental natures of electromagnetic radiation. The detection of polarization or polarized photons from distant X-ray radiating systems (such as X-ray binaries (XBs), active galactic nuclei (AGN), pulsars, and…

High Energy Astrophysical Phenomena · Physics 2026-01-01 Arbind Pradhan , Sree Bhattacherjee , Biplob Sarkar

Polarimetric radio observations of the Sun can provide rich information about emission mechanisms and the propagation medium. For the past five decades, solar polarimetric studies at low radio frequencies have almost always assumed the…

Solar and Stellar Astrophysics · Physics 2025-08-05 Soham Dey , Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

We continue our studies of atomic alignment in diffuse media, in particularly, in interstellar and circumstellar media, with the goal of developing new diagnostics of magnetic fields in these environments. We understand atomic alignment as…

Astrophysics · Physics 2009-11-13 Huirong Yan , A. Lazarian

The advent of sensitive polarimeters on large telescopes has led to a revolution in our understanding of active galaxies over the last 20 years. In the case of powerful radio galaxies the deep polarimetric measurements made possible by the…

Astrophysics · Physics 2007-05-23 Clive Tadhunter

We revisit the classification of polarization observables of the cosmic microwave background. There exists a unified approach to the $3 \times 3$ density matrix by which intensity, linear and circular polarization are treated on an equal…

Astrophysics · Physics 2007-05-23 John P. Ralston , Pankaj Jain