English
Related papers

Related papers: Coherent Emission

200 papers

We explore the physics of electron acceleration in a plasma medium in an effective field theory framework. Employing a multiple Compton scattering mechanism, it is found that the acceleration can be sustained in such a medium so as to…

Plasma Physics · Physics 2013-03-07 Ravindra Kumar , V. Ravishankar

We propose a new way to observe cosmic-ray-induced air showers by imaging the radio emission. With simulations we demonstrate key features for imaging the radio-wave emission from air showers, which show similarities to the well-established…

High Energy Astrophysical Phenomena · Physics 2026-05-18 Juan Ammerman-Yebra , Harm Schoorlemmer , Anne Timmermans , Sebastian Achim Mueller

The radio signal transmitted by the Mars Express (MEX) spacecraft was observed regularly between the years 2013-2020 at X-band (8.42 GHz) using the European Very Long Baseline Interferometry (EVN) network and University of Tasmania's…

We have examined the cyclotron resonance instability developing in the relativistic out-flowing plasma in the pulsar magnetosphere. The instability condition leads to radio emission in the sub-GHz frequency regime which is likely to be seen…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Rahul Basu , Dipanjan Mitra , George I. Melikidze

We suggest that pairing of bouncing medium-energy electrons in the auroral upward current region close to the mirror points may play a role in driving the electron cyclotron maser instability to generate an escaping narrow band fine…

Space Physics · Physics 2020-10-08 R. A. Treumann , Wolfgang Baumjohann

Fast radio bursts are mysterious transient sources likely located at cosmological distances. The derived brightness temperatures exceed by many orders of magnitude the self-absorption limit of incoherent synchrotron radiation, implying the…

High Energy Astrophysical Phenomena · Physics 2016-01-20 Gustavo E. Romero , Maria Victoria del Valle , Florencia L. Vieyro

A relativistic pair-plasma which contains a high excitation of electrostatic turbulence could produce intense radiation at brightness temperature in excess of 10^22 K by stimulated scattering. Important relativistic effects would include…

Astrophysics · Physics 2009-11-07 James C. Weatherall

We present the first observation of an instability in an expanding ultracold plasma. We observe periodic emission of electrons from an ultracold plasma in weak, crossed magnetic and electric fields, and a strongly perturbed electron density…

Plasma Physics · Physics 2008-11-06 X. L. Zhang , R. S. Fletcher , S. L. Rolston

In this paper we re-analyse the amplification process of broadband continuum radiation by astronomical masers in one-dimensional case. The basic equations appropriate for the scalar maser and the random nature of the maser radiation field…

Astrophysics of Galaxies · Physics 2015-05-13 Dinh-V-Trung

Blazars are a sub-category of radio-loud active galactic nuclei with relativistic jets pointing towards to the observer. They are well-known for their non-thermal variable emission, which practically extends over the whole electromagnetic…

High Energy Astrophysical Phenomena · Physics 2019-01-28 Stella Boula , Maria Petropoulou , Apostolos Mastichiadis

Recent results, the present status and the perspectives of high energy gamma-ray astronomy are described. Since the satellite observations by the Compton Gamma Ray Observatory and its precursor missions have been reviewed extensively,…

Astrophysics · Physics 2009-11-07 Heinrich J. Völk

Radio emission is a good indicator of the jet power of radio-loud quasars, while the emission in broad-line can well represent the accretion disc radiation in quasars. We compile a sample of all sources of which the broad-line fluxes are…

Astrophysics · Physics 2009-10-31 Xinwu Cao , D. R. Jiang

We discuss a theoretical interpretation of the experiment by Fletcher, Zhang, and Rolston [PRL, 96, 105003 (2006)], who revealed a number of subharmonics of the electron emission under external irradiation of the freely-expanding clouds of…

Plasma Physics · Physics 2009-06-30 Yurii V. Dumin

Pulsars are neutron stars, stellar corpses left over after supernova explosions of stars about ten times as massive as our Sun, with densities comparable to the atomic nucleus', spinning with periods from few milliseconds up to few seconds,…

We model the off-resonant superradiant Raman scattering of light from a cigar-shaped atomic Bose-Einstein condensate. Absorption images of transmitted light serve as a direct probe of long range coherence in the condensate. Our multimode…

Other Condensed Matter · Physics 2015-06-25 H. Uys , P. Meystre

Although they were discovered more than 25 years ago, gamma-ray bursts are still a mystery. Even their characteristic distance is highly uncertain. All that we can be confident about is that they involve compact objects and relativistic…

Astrophysics · Physics 2007-05-23 Martin J. Rees

Codalema is one of the experiments devoted to the detection of ultra high energy cosmic rays by the radio method. The main objective is to study the features of the radio signal induced by the development in the atmosphere of extensive air…

High Energy Astrophysical Phenomena · Physics 2012-11-15 Ahmed Rebai

This paper summarizes recents results in gamma-ray astronomy, most of which were derived with data from ground-based gamma-ray detectors. Many of the contributions presented at this conference involve multiwavelength studies which combine…

Astrophysics · Physics 2007-05-23 Martin Pohl

We investigate a possible origin for bursty radio emission observed on the active M dwarf V374 Peg, combining data-driven magnetic field modelling with archival radio light curves. We examine whether stellar prominence ejection can…

Solar and Stellar Astrophysics · Physics 2026-01-08 C. E. Brasseur , M. M. Jardine , S. Daley-Yates , J. F. Donati , J. Morin

We consider the widespread assumption that coherent pulsar radio emission is based on extended pair production leading to plasma densities highly exceeding the Goldreich-Julian density. We show as an example that the observed low frequency…

Astrophysics · Physics 2009-10-30 Thomas Kunzl , Harald Lesch , Axel Jessner , Alexis von Hoensbroech