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Related papers: Deducing Electron Properties From Hard X-Ray Obser…

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Regularized imaging spectroscopy was introduced for the construction of electron flux images at different energies from count visibilities recorded by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). In this work we seek…

Solar and Stellar Astrophysics · Physics 2023-11-14 Anna Volpara , Paolo Massa , Sam Krucker , A Gordon Emslie , Michele Piana , Anna Maria Massone

With the elementary energy release events introduced in a previous paper (Liu & Fletcher 2009) we model the chromospheric evaporation in flaring loops. The thick-target hard X-ray (HXR) emission produced by electrons escaping from the…

Solar and Stellar Astrophysics · Physics 2014-11-20 Siming Liu , Feiran Han , Lyndsay Fletcher

Polarization dependence has historically seen extensive use in x-ray spectroscopy to determine magnetic and local geometric properties, but more broadly as a way to gain extra sensitivity to electronic structure at the level of individual…

Spectroscopic observations in X-ray wavelengths provide excellent diagnostics of the temperature distribution in solar flare plasma. The Solar X-ray Monitor (XSM) onboard the Chandrayaan-2 mission provides broad-band disk integrated soft…

Compton scattering is a key process shaping spectra formation and accretion flow dynamics in accreting strongly magnetized neutron stars. A strong magnetic field affects the scattering cross section and makes it dependent on photon energy,…

We identify a set of ~100 "cold" solar flares and perform a statistical analysis of them in the microwave range. Cold flares are characterized by a weak thermal response relative to nonthermal emission. This work is a follow up of a…

The newly developed X-ray visibility forward fitting technique is applied to Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) data of a limb flare to investigate the energy and height dependence on sizes, shapes, and position…

Solar and Stellar Astrophysics · Physics 2015-05-18 E. P. Kontar , I. G. Hannah , N. L. S. Jeffrey , M. Battaglia

Sudden jets of collimated plasma arise from many locations on the Sun, including active regions. The magnetic field along which a jet emerges is often open to interplanetary space, offering a clear "escape route" for any flare-accelerated…

Solar and Stellar Astrophysics · Physics 2018-11-07 Lindsay Glesener , Gregory D. Fleishman

Spectrograph is an optical device that is used to disperse photons of different energies $E$ into distinct directions and space locations, and to take a snapshot of the whole spectrum of photon energies with a spatially sensitive photon…

Optics · Physics 2015-06-03 Yuri Shvyd'ko

We use Monte Carlo approach to study the energetics of electrons accelerated in a pulsar polar gap. As energy-loss mechanisms we consider magnetic Compton scattering of thermal X-ray photons and curvature radiation. The results are compared…

Astrophysics · Physics 2007-05-23 J. Dyks , B. Rudak

Coronae express different facets of their energy release processes in different wavelength regions. While soft X-ray and EUV emission dominates the radiative losses of the thermal plasma, hard X-ray emission (>10 keV) can be produced from…

Astrophysics · Physics 2007-05-23 Manuel Guedel

In a standard method of determining electron density for soft X-ray (SXR) flare kernels it is necessary to assume what is the extension of a kernel along the line of sight. This is a source of significant uncertainty of the obtained…

Solar and Stellar Astrophysics · Physics 2015-05-27 Jerzy Jakimiec , Urszula Bak-Steslicka

Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic 3D modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration…

Solar and Stellar Astrophysics · Physics 2015-06-15 Gregory D. Fleishman , Eduard P. Kontar , Gelu M. Nita , Dale E. Gary

Hard x-ray spectral breaks are explained in terms of a 1D model with a co-spatial return current. We study 19 flares observed by RHESSI (Ramaty High Energy Solar Spectroscopic Imager) with strong spectral breaks at energies around a few…

Solar and Stellar Astrophysics · Physics 2018-01-08 Meriem Alaoui , Gordon Holman

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Marina Battaglia , Eduard P. Kontar

X-ray polarimetry has great scientific potential and new experiments, such as X-Calibur, PoGOLite, XIPE, and GEMS, will not only be orders of magnitude more sensitive than previous missions, but also provide the capability to measure…

Instrumentation and Methods for Astrophysics · Physics 2015-03-03 Fabian Kislat , Matthias Beilicke , Qingzhen Guo , Anna Zajczyk , Henric Krawczynski

IXPE has enabled the X-ray polarizations of many blazars to be measured. We analyze X-ray spectropolarimetric data for all high synchrotron peaked blazars observations published by the IXPE team. We find that there are no statistically…

High Energy Astrophysical Phenomena · Physics 2025-06-23 M. Lynne Saade , Steven Ehlert , Ioannis Liodakis , Philip Kaaret , Fabrizio Tavecchio

We studied electron spectral indices of nonthermal emissions seen in hard X-rays (HXRs) and in microwaves. We analyzed 12 flares observed by the Hard X-ray Telescope aboard {\it Yohkoh}, Nobeyama Radio Polarimeters (NoRP), and the Nobeyama…

The distribution function of electrons and phonons interacting with electrons in semiconductors and semimetals in high electric and quantizing magnetic fields as a result of the solution of the coupled system of equations for the density…

Condensed Matter · Physics 2007-05-23 T. M. Gassym

Emission spectra from magnetars in the soft X-ray band likely contain a thermal component emerging directly from the neutron star surface. However, the lack of observed absorption-like features in quiescent spectra makes it difficult to…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Matthew van Adelsberg , Rosalba Perna