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Related papers: Circular Polarization from Gamma-ray Burst Aftergl…

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The afterglows to gamma-ray bursts (GRBs) are due to synchrotron emission from shocks generated as an ultra-relativistic outflow decelerates. A forward and a reverse shock will form, however, where emission from the forward shock is well…

High Energy Astrophysical Phenomena · Physics 2019-09-04 Gavin P Lamb , Shiho Kobayashi

We report the earliest-ever detection of optical polarization from a GRB forward shock (GRB 141220A), measured $129.5-204.3\,$s after the burst using the multi-colour RINGO3 optical polarimeter on the 2-m fully autonomous robotic Liverpool…

High Energy Astrophysical Phenomena · Physics 2021-06-22 N. Jordana-Mitjans , C. G. Mundell , R. J. Smith , C. Guidorzi , M. Marongiu , S. Kobayashi , A. Gomboc , M. Shrestha , I. A. Steele

The curvature radiation is applied to the explain the circular polarization of FRBs. Significant circular polarization is reported in both apparently non-repeating and repeating FRBs. Curvature radiation can produce significant circular…

High Energy Astrophysical Phenomena · Physics 2022-06-29 H. Tong , H. G. Wang

Tangled, primordial cosmic magnetic fields create small rotational velocity perturbations on the last scattering surface (LSS) of the cosmic microwave background radiation (CMBR). For fields which redshift to a present value of $B_0 =…

Astrophysics · Physics 2009-10-31 T. R. Seshadri , Kandaswamy Subramanian

Among the large variety of astrophysical sources that we can observe, gamma-ray bursts (GRBs) are the most energetic of the whole Universe. The definition of a general picture describing the physics behind GRBs has always been a compelling…

High Energy Astrophysical Phenomena · Physics 2022-10-26 R. Brivio , S. Covino , P. D'Avanzo , K. Wiersema , J. R. Maund , M. G. Bernardini , S. Campana , A. Melandri

Circularly-polarized (CP) vibrations are the nuclear-motion analog of CP light, emerging in molecules with non-Abelian point-group symmetry that support orthogonal and degenerate vibrational normal modes. Here, we explore the optical…

Chemical Physics · Physics 2025-06-27 Chientzu Lin , Connor K. Terry Weatherly , Roel Tempelaar

We show that the absence of the bright optical flashes in most {\it Swift} Gamma-ray Burst (GRB) afterglows can be explained, if the reverse shock region is magnetized with a $\sigma \sim 1$, or the emission spectrum of the electrons…

Astrophysics · Physics 2009-11-13 Yi-Zhong Fan

Circularly polarized (CP) $\gamma$-ray sources are versatile for broad applications in nuclear physics, high-energy physics and astrophysics. The laser-plasma based particle accelerators provide accessibility for much higher flux…

We present a model-independent way to characterise properties of the magnetic-field turbulence in the emitting regions of Gamma-Ray Burst afterglows. Our only assumption is that afterglows' synchrotron radiation is efficient. It turns out…

High Energy Astrophysical Phenomena · Physics 2024-11-20 Evgeny Derishev

Gamma-ray bursts (GRBs) are powered by ultra-relativistic jets. The launching sites of these jets are surrounded by dense media, which the jets must cross before they can accelerate and release the high energy emission. Interaction with the…

High Energy Astrophysical Phenomena · Physics 2024-10-22 Gal Birenbaum , Ramandeep Gill , Omer Bromberg , Paz Beniamini , Jonathan Granot

We present photometric and polarimetric measurements of gamma-ray burst (GRB) optical afterglows observed by the RINGO3 imaging polarimeter over its $\sim$7 year lifetime mounted on the Liverpool Telescope. During this time, RINGO3…

High Energy Astrophysical Phenomena · Physics 2022-08-24 M. Shrestha , I. A. Steele , S. Kobayashi , R J. Smith , C. Guidorzi , N. Jordana-Mitjans , H. Jermak , D. Arnold , C. G. Mundell , A. Gomboc

The standard scenario of cosmology predicts a measurable amount for linear polarization of the Cosmic Microwave Background radiation (CMB) via Thomson scattering, while through this scenario, the generation of circular polarization is…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-04 Ali Vahedi , Jafar Khodagholizadeh , Rohoollah Mohammadi , Mahdi Sadegh

By Polnarev's method we analytically calculate the polarization spectra of the cosmic microwave background radiation (CMB) generated by cosmic relic gravitational waves (RGW). In this analytic approach the physics involved in this…

Astrophysics · Physics 2008-11-26 Wen Zhao , Yang Zhang

A high-degree of polarization of gamma-ray burst (GRB) prompt emission has been confirmed in recent years. In this paper, we apply jitter radiation to study the polarization feature of GRB prompt emission. In our framework, relativistic…

High Energy Astrophysical Phenomena · Physics 2015-06-17 J. Mao , J. Wang

Evidence suggests that the gamma-ray burst (GRB) ejecta is likely magnetized, although the degree of magnetization of the ejecta is unknown. We derive a rigorous analytical solution for the relativistic 90 degree shocks under the ideal MHD…

Astrophysics · Physics 2009-11-10 Bing Zhang , Shiho Kobayashi

We report the first detections of circularly polarized emission at submillimeter wavelengths from the compact radio source and supermassive black hole candidate Sgr A* at a level of 1.2\pm0.3% at 1.3 mm wavelength (230 GHz) and 1.6\pm0.3%…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Diego J. Muñoz , Daniel P. Marrone , James M. Moran , Ramprasad Rao

Polarization observations provide a unique way to probe the nature of jet magnetic fields in gamma-ray bursts (GRBs). Currently, some GRBs have been detected to be polarized in their early optical afterglows. However, the measured…

High Energy Astrophysical Phenomena · Physics 2024-11-26 Bao-Quan Huang , Tong Liu , Guo-Yu Li

The radiation from afterglows of gamma-ray bursts is generated in the collisionless plasma shock interface between a relativistic outflow and a quiescent circum-burst medium. The two main ingredients responsible for the radiation are…

Astrophysics · Physics 2007-05-23 Christian Busk Hededal , Åke Nordlund

The circular polarization of the cosmic microwave background (CMB) is usually taken to be zero since it is not generated by Thomson scattering. Here we explore the actual level of circular polarization in the CMB generated by conventional…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-30 Paulo Montero-Camacho , Christopher M. Hirata

The degree and the temporal evolution of linear polarization in the prompt and afterglow emission of gamma-ray bursts is a very robust diagnostic of some key features of gamma-ray bursts jets and their micro and macro physics. In this…

High Energy Astrophysical Phenomena · Physics 2016-06-01 Davide Lazzati
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