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Related papers: Maser polarization through anisotropic pumping

200 papers

Proton-induced knockout reactions at intermediate energies provide a clean probe for nuclear clusters with relatively small theoretical uncertainties. The Maris polarization, which is the effective polarization of a particle inside a…

Nuclear Theory · Physics 2025-11-24 Yoshiki Chazono

An astrophysical MASER (Microwave Amplification by Stimulated Emission of Radiation) is a source of stimulated spectral line emission. Maser emission is observed from the circumstellar envelopes of evolved stars, molecular…

Instrumentation and Methods for Astrophysics · Physics 2011-04-13 Elizabeth Humphreys

Since the first detection by the DASI experiment in 2002, measurements of the polarization of the cosmic microwave background (CMB) have grown into an important role in testing our understanding of conditions in the early universe and…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-06 M. Rahimi , C. L. Reichardt

We provide a new analysis technique to measure the effect of the isotropic polarization rotation, induced by e.g. the isotropic cosmic birefringence from axion-like particles and a miscalibration of CMB polarization angle, via mode coupling…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-30 Toshiya Namikawa

Through polarization observations, circumstellar masers are excellent probes of the magnetic field in the envelopes of late-type stars. Whereas observations of the polarization of the SiO masers close to the star and on the OH masers much…

Astrophysics · Physics 2009-11-10 W. H. T. Vlemmings , H. J. van Langevelde , P. J. Diamond

The collisional pumping of CH3OH and OH masers in non-dissociative C-type shock waves is studied. The chemical processes responsible for the evolution of molecule abundances in the shock wave are considered in detail. The large velocity…

Astrophysics of Galaxies · Physics 2021-12-15 A. V. Nesterenok

This paper examines the detailed sub-milliarcsecond polarization properties of an individual SiO maser feature displaying a rotation in polarization electric vector position angle of approximately \pi/2 across the feature. Such rotations…

Solar and Stellar Astrophysics · Physics 2015-05-30 A. J. Kemball , P. J. Diamond , L. Richter , I. Gonidakis , R. Xue

The anisotropy of velocities in MHD turbulence is demonstrated explicitly by calculating the velocity gradients as a function of direction in representative simulations of decaying turbulence. It follows that the optical depths of spectral…

Astrophysics · Physics 2008-11-26 D. S. Wiebe , W. D. Watson

Polarisation effects in the microcavity parametric oscillator are studied using a simple model in which two chi-three optical parametric oscillators are coupled together. It is found that there are, in general, a number of steady states of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. R. Eastham , D. M. Whittaker

The 1612 and 1667 MHz OH maser lines have been measured in all four Stokes parameters in 47 proto-planetary nebula (PPN) candidates. Out of 42 objects detected, 40 and 34 are 1612 and 1667 MHz emitters, respectively. The spectral extent of…

Astrophysics · Physics 2009-11-10 M. Szymczak , E. Gerard

We consider the role of a propagation effect such as the stimulated Raman scattering on the polarization of radio pulses. When an intense electromagnetic wave with frequency close to the plasma frequency interacts with the plasma in the…

Astrophysics · Physics 2009-10-31 R. T. Gangadhara , H. Lesch , V. Krishan

We study experimentally and theoretically polarization-dependent luminescence from an ensemble of quantum-dot-like nanostructures with a very large in-plane shape anisotropy (quantum dashes). We show that the measured degree of linear…

Mesoscale and Nanoscale Physics · Physics 2012-01-20 A. Musiał , P. Kaczmarkiewicz , G. Sęk , P. Podemski , P. Machnikowski , J. Misiewicz , S. Hein , S. Höfling , A. Forchel

NGC7538 is a complex massive star-forming region. The region is composed of several radio continuum sources, one of which is IRS1, a high-mass protostar, from which a 0.3 pc molecular bipolar outflow was detected. Several maser species have…

Solar and Stellar Astrophysics · Physics 2015-05-28 G. Surcis , W. H. T. Vlemmings , R. M. Torres , H. J. van Langevelde , B. Hutawarakorn Kramer

Polarization induced by cosmological scalar perturbations leads to a typical anisotropy pattern, which can best be analyzed in Fourier domain. This allows one to unambiguously distinguish cosmological signal of polarization from other…

Astrophysics · Physics 2009-10-28 Uros Seljak

The Australia Telescope Compact Array (ATCA) has been used to make the first full polarization observations of 6.7 GHz methanol masers. Linear polarization was detected towards all four sources observed, at levels between a few and 10%,…

Astrophysics · Physics 2007-05-23 S. P. Ellingsen

This article presents an introduction to optical pumping, atomic polarization and the Hanle effect in weakly magnetized stellar atmospheres. Although the physical processes and the theoretical framework described here are of interest for…

Astrophysics · Physics 2007-05-23 Javier Trujillo-Bueno

The general model for incoherent synchrotron radiation has long been known, with the first theory being published by Westfold in $1959$ and continued by Westfold and Legg in $1968$. When this model was first developed it was applied to…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Diarmaid de Búrca , Andrew Shearer

Pulsar radio emission is modelled as a sum of two completely polarized non-orthogonal modes with the randomly varying Stokes parameters and intensity ratio. The modes are the result of polarization evolution of the original natural waves in…

Astrophysics · Physics 2009-11-11 S. A. Petrova

The density matrix, \rho, of a model polariton system is obtained numerically from a master equation which takes account of pumping and losses. In the stationary limit, the coherences between eigenstates of the Hamiltonian are three orders…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Carlos Andres Vera , Alejandro Cabo , Augusto Gonzalez

We present full resolution (~0.2mas, ~0.1 A.U.) Very Long Baseline Interferometry maps of the v=1, J=1-0 SiO masers in the Orion-KL nebula. The morphology and turbulent nature of the maser emission argues against models in which the masers…

Astrophysics · Physics 2007-05-23 Sheperd Doeleman Colin Lonsdale Shannon Pelkey