Author: Markus Aschwanden
Publisher: Springer Science & Business Media
ISBN: 9401725411
Category : Science
Languages : en
Pages : 233
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Book Description
Over the last decade we entered a new exploration phase of solar flare physics, equipped with powerful spacecraft such as Yohkoh, SoHO, and TRACE that pro vide us detail-rich and high-resolution images of solar flares in soft X-rays, hard X -rays, and extreme-ultraviolet wavelengths. Moreover, the large-area and high sensitivity detectors on the Compton GRO spacecraft recorded an unprecedented number of high-energy photons from solar flares that surpasses all detected high energy sources taken together from the rest of the universe, for which CGRO was mainly designed to explore. However, morphological descriptions of these beau tiful pictures and statistical catalogs of these huge archives of solar data would not convey us much understanding of the underlying physics, if we would not set out to quantify physical parameters from these data and would not subject these measurements to theoretical models. Historically, there has always been an unsatisfactory gap between traditional astronomy that dutifully describes the mor phology of observations, and the newer approach of astrophysics, which starts with physical concepts from first principles and analyzes astronomical data with the goal to confirm or disprove theoretical models. In this review we attempt to bridge this yawning gap and aim to present the recent developments in solar flare high-energy physics from a physical point of view, structuring the observations and analysis results according to physical processes, such as particle acceleration, propagation, energy loss, kinematics, and radiation signatures.
Author: Guangli Huang
Publisher: Springer
ISBN: 9811028699
Category : Science
Languages : en
Pages : 437
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Book Description
This book provides results of analysis of typical solar events, statistical analysis, the diagnostics of energetic electrons and magnetic field, as well as the global behavior of solar flaring loops such as their contraction and expansion. It pays particular attention to analyzing solar flare loops with microwave, hard X-ray, optical and EUV emissions, as well as the theories of their radiation, and electron acceleration/transport. The results concerning influence of the pitch-angle anisotropy of non-thermal electrons on their microwave and hard X-ray emissions, new spectral behaviors in X-ray and microwave bands, and results related to the contraction of flaring loops, are widely discussed in the literature of solar physics. The book is useful for graduate students and researchers in solar and space physics.
Author: Karl L. Klein
Publisher: Springer
ISBN: 3540715703
Category : Science
Languages : en
Pages : 288
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Book Description
An outgrow of an earlier workshop held by the community of European Solar Radio Astronomers (CESRA), this topical volume collects reviews on the current multiwavelength findings and perspectives from the space missions RHESSI, TRACE and SOTTO. The aspects of solar physics dealt with are particle acceleration during flares, large-scale disturbances, and coronal plasma physics.
Author: Markus Aschwanden
Publisher: Springer Science & Business Media
ISBN: 9783540307655
Category : Science
Languages : en
Pages : 946
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Book Description
A thorough introduction to solar physics based on recent spacecraft observations. The author introduces the solar corona and sets it in the context of basic plasma physics before moving on to discuss plasma instabilities and plasma heating processes. The latest results on coronal heating and radiation are presented. Spectacular phenomena such as solar flares and coronal mass ejections are described in detail, together with their potential effects on the Earth.
Author: Marina Battaglia
Publisher: Cuvillier Verlag
ISBN: 3736928807
Category : Science
Languages : en
Pages : 161
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Book Description
This thesis is devoted to the study of particle acceleration and propagation processes in solar flares. Solar flares are amongst the most powerful and energetic activity phenomena our Sun exhibits. They release energy of the order of 1032 erg in seconds to minutes. In the process, electrons and protons are accelerated to relativistic energies, making flares very efficient particle accelerators. The most compelling observational signatures of flares can be found in X-rays and extreme ultra-violet wavelengths. Due to atmospheric absorption, those wavelengths can only be studied from space. Since the beginning of the space age, countless flares have been observed by satellites. The present work is largely based on observations by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), an X-ray satellite which has been observing the Sun since February 2002. It is a NASA mission with substantial Swiss hardware and software contribution. Using RHESSI observations of flares of different intensity, a deeper understanding of the particle transport and energy transport processes in flare loops, as well as the acceleration site and acceleration mechanism is sought. The time evolution of images and spectra is studied along with the quantitative relations between X-ray sources observed in the corona (coronal sources) and from the chromosphere (footpoints). The spectral relations found between coronal sources and footpoints are compared to the so-called ``intermediate thin-thick target model'', which was based on observations by the satellite Yohkoh. We show that the spectral relations between coronal sources and footpoints observed with RHESSI cannot be explained by the intermediate thin-thick target model. In a next step, return currents in the flare loop were considered. With this extension to the existing model, the spectra of the coronal source and the footpoints, as well as the relations between them can be explained, indicating the importance of return currents in flare loops. In a second part, observations of so-called ``pre-flares'' are presented. This earliest phase of a flare cannot be explained by the standard flare model of chromospheric evaporation which involves energy transport and deposition in the chromosphere by beams of accelerated electrons. In pre-flares, an increase in density and emission measure is observed, indicating that chromospheric evaporation is occurring. However, no observational signatures of fast electrons are found. We show that if energy is transported by means of thermal conduction instead of an electron beam, the observations can explained.
Author: G. Trottet
Publisher: Springer Science & Business Media
ISBN: 940093999X
Category : Science
Languages : en
Pages : 236
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Book Description
These are the Proceedings of the Second CESRA Workshop on Particle Acceleration and Trapping in Solar Flares. The Workshop was held on June 23-26,1986, at the city hall of Aubigny-sur-Nere (France), near Bourges and near the Nan
Author: Brian R. Dennis
Publisher:
ISBN:
Category : Particle acceleration
Languages : en
Pages : 376
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Book Description
Author: Gérard Trottet
Publisher:
ISBN:
Category : Heliosphere
Languages : en
Pages : 246
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Book Description
Author: International Astronomical Union. Symposium
Publisher: Cambridge University Press
ISBN: 9780521874694
Category : Science
Languages : en
Pages : 404
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Book Description
Provides the latest summary on the solar coronal heating enigma and magneto-seismology of the solar atmosphere, for solar physics researchers.
Author: Anand K. Bhatia
Publisher: MDPI
ISBN: 303943795X
Category : Mathematics
Languages : en
Pages : 126
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Book Description
Positrons can be used to study metallic defects. Positron annihilation experiments have been carried out to identify the defects in complex oxides. Positrons have also been used to study the Bose–Einstein condensation (BEC). Ps-BEC can be used to measure antigravity using atomic interferometers. This Special Issue hopes to bring awareness of the various aspects of positron interactions to the larger physics communities. We invite authors to submit articles from all areas of physics.
