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The Reuven Ramaty High Energy Spectroscopic Solar Imager (RHESSI) uses the rotational modulation principle to observe temporally, spatially, and spectrally resolved hard X ray and gamma ray images of solar flares. In order to track the…

Astrophysics · Physics 2009-11-10 Kaspar Arzner

One way of imaging X-ray emission from solar flares is to measure Fourier components of the spatial X-ray source distribution. We present a new Compressed Sensing-based algorithm named VIS_CS, which reconstructs the spatial distribution…

Solar and Stellar Astrophysics · Physics 2017-11-01 Simon Felix , Roman Bolzern , Marina Battaglia

This paper is concerned with the image reconstruction problem when the measured data are solar hard X-ray modulation profiles obtained from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI)} instrument. Our goal is to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Federico Benvenuto , Richard Schwartz , Michele Piana , Anna Maria Massone

High-energy X-rays and gamma-rays from solar flares were discovered just over fifty years ago. Since that time, the standard for the interpretation of spatially integrated flare X-ray spectra at energies above several tens of keV has been…

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

The Spectrometer/Telescope for Imaging X-rays (STIX) will look at solar flares across the hard X-ray window provided by the Solar Orbiter cluster. Similarly to the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), STIX is a…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Paolo Massa , Michele Piana , Anna Maria Massone , Federico Benvenuto

Space telescopes for solar hard X-ray imaging provide observations made of sampled Fourier components of the incoming photon flux. The aim of this study is to design an image reconstruction method relying on enhanced visibility…

Instrumentation and Methods for Astrophysics · Physics 2021-10-13 Emma Perracchione , Paolo Massa , Anna Maria Massone , Michele Piana

The model of stochastic acceleration of particles by turbulence has been successful in explaining many observed features of solar flares. Here we demonstrate a new method to obtain the accelerated electron spectrum and important…

Solar and Stellar Astrophysics · Physics 2015-05-18 Vahe Petrosian , Qingrong Chen

The deduction from solar flare X-ray photon spectroscopic data of the energy dependent model-independent spectral index is considered as an inverse problem. Using the well developed regularization approach we analyze the energy dependency…

Astrophysics · Physics 2009-11-11 Eduard P. Kontar , Alexander L. MacKinnon

We describe two inversion methods for the reconstruction of hard X-ray solar images. The methods are tested against experimental visibilities recorded by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and synthetic…

Solar and Stellar Astrophysics · Physics 2019-07-17 Anna Maria Massone , Federica Sciacchitano , Michele Piana , Alberto Sorrentino

We present a concept for a machine-learning classification of hard X-ray (HXR) emissions from solar flares observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), identifying flares that are either occulted by the…

Solar and Stellar Astrophysics · Physics 2021-02-24 Shin-nosuke Ishikawa , Hideaki Matsumura , Yasunobu Uchiyama , Lindsay Glesener

We present a new analytical technique, combining Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) high-resolution imaging and spectroscopic observations, to visualize solar flare emission as a function of spectral component…

Instrumentation and Methods for Astrophysics · Physics 2015-09-15 Amir Caspi , Albert Y. Shih , James M. McTiernan , Säm Krucker

Quantitative and analytical analysis of modulation process of the collimator is a great challenge, and is also of great value to the design and development of Fourier transform imaging telescopes. The Hard X-ray Imager (HXI), as one of the…

Instrumentation and Methods for Astrophysics · Physics 2023-02-01 Xian-Kai Jiang , Jian Wu , Deng-Yi Chen , Yi-Ming Hu , Hao-Xiang Wang , Wei Liu , Zhe Zhang

Kontar et al. (2004) have shown how to recover mean source electron spectra in solar flares through a physical constraint regularization analysis of the bremsstrahlung photon spectra that they produce. They emphasize the use of non-square…

Astrophysics · Physics 2009-11-10 E. P. Kontar , A. G. Emslie , M. Piana , A. M. Massone , J. C. Brown

The imaging spectroscopy capabilities of the Reuven Ramaty high energy solar spectroscopic imager (RHESSI) enable the examination of the accelerated electron distribution throughout a solar flare region. In particular, it has been revealed…

Solar and Stellar Astrophysics · Physics 2018-04-25 Duncan J. Stackhouse , Eduard P. Kontar

Polarization measurements of hard X-rays from solar flares can provide a direct handle on the extent to which the accelerated electrons are beamed, which, in turn, has important implications for particle acceleration models. Past efforts to…

Astrophysics · Physics 2009-11-07 M. L. McConnell , J. M. Ryan , D. M. Smith , R. P. Lin , A. G. Emslie

The RHESSI experiment uses rotational modulation for x- and gamma ray imaging of solar eruptions. In order to disentangle rotational modulation from intrinsic time variation, an unbiased linear estimator for the spatially integrated photon…

Astrophysics · Physics 2009-11-10 Kaspar Arzner

We present a new method, fan-beam modulation, for observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). This space-based solar x-ray and gamma-ray telescope has much greater…

Astrophysics · Physics 2008-11-26 Iain G. Hannah , Gordon J. Hurford , Hugh S. Hudson , Robert P. Lin

We describe a new technique to measure the height of the X-ray limb with observations from occulted X-ray flare sources as observed by the RHESSI (the Reuven Ramaty High-Energy Spectroscopic Imager) satellite. This method has model…

Solar and Stellar Astrophysics · Physics 2017-07-26 Marina Battaglia , Hugh S. Hudson , Gordon J. Hurford , Säm Krucker , Richard A. Schwartz

X-rays are a valuable diagnostic tool for the study of high energy accelerated electrons. Bremsstrahlung X-rays produced by, and directly related to, high energy electrons accelerated during a flare, provide a powerful diagnostic tool for…

Solar and Stellar Astrophysics · Physics 2015-03-09 Natasha L. S. Jeffrey
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