Download or read book Faint Coronal Hard X rays From Accelerated Electrons in Solar Flares written by Lindsay Erin Glesener and published by . This book was released on 2012 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar flares are huge explosions on the Sun that release a tremendous amount of energy from the coronal magnetic field, up to 1033 ergs, in a short time (100--1000 seconds), with much of the energy going into accelerated electrons and ions. An efficient acceleration mechanism is needed, but the details of this mechanism remain relatively unknown. A fraction of this explosive energy reaches the Earth in the form of energetic particles, producing geomagnetic storms and posing dangers to spaceborne instruments, astronauts, and Earthbound power grids. There are thus practical reasons, as well as intellectual ones, for wishing to understand this extraordinary form of energy release. Through imaging spectroscopy of the hard X-ray (HXR) emission from solar flares, the behavior of flare-accelerated electrons can be studied. The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft launched in 2002 with the goal of better understanding flare particle acceleration. Using rotation modulation collimators, RHESSI is able to cover a wide energy range (3 keV--17 MeV) with fine angular and energy resolutions. RHESSI's success in the last 10 years in investigating the relationship between energetic electrons and ions, the nature of faint sources in the corona, the energy distribution of flares, and several other topics have significantly advanced the understanding of flares. But along with the wealth of information revealed by RHESSI come some clear observational challenges. Very few, if any, RHESSI observations have come close to imaging the electron acceleration region itself. This is undoubtedly due to a lack of both sensitivity (HXRs from electron beams in the tenuous corona are faint) and dynamic range (HXR sources at chromospheric flare footpoints are much brighter and tend to obscure faint coronal sources). Greater sensitivity is also required to investigate the role that small flares in the quiet Sun could play in heating the corona. The Focusing Optics X-ray Solar Imager (FOXSI) is a developing project to address these observational difficulties. FOXSI is a sounding rocket payload developed under NASA's Low Cost Access to Space program. The project spearheads a shift to using direct imaging via focusing grazing-incidence HXR optics rather than the indirect Fourier techniques used by RHESSI and its predecessors. Such optics can attain higher sensitivity since photons are focused onto a small detector volume and have significantly better dynamic range than Fourier methods do. On November 2, 2012 the FOXSI rocket payload was flown for a 6-minute observation and successfully imaged a solar flare, providing the first focused HXR spectroscopic images of the Sun above 5 keV. The motivation, construction, testing, and flight of FOXSI will be described in this text, along with case studies on the use of FOXSI to analyze unique coronal HXR sources from two solar flares.
Download or read book Hard X Ray Imaging of Solar Flares written by Michele Piana and published by Springer Nature. This book was released on 2022-01-01 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea for this text emerged over several years as the authors participated in research projects related to analysis of data from NASA's RHESSI Small Explorer mission. The data produced over the operational lifetime of this mission inspired many investigations related to a specific science question: the when, where, and how of electron acceleration during solar flares in the stressed magnetic environment of the active Sun. A vital key to unlocking this science problem is the ability to produce high-quality images of hard X-rays produced by bremsstrahlung radiation from electrons accelerated during a solar flare. The only practical way to do this within the technological and budgetary limitations of the RHESSI era was to opt for indirect modalities in which imaging information is encoded as a set of two-dimensional spatial Fourier components. Radio astronomers had employed Fourier imaging for many years. However, differently than for radio astronomy, X-ray images produced by RHESSI had to be constructed from a very limited number of sparsely distributed and very noisy Fourier components. Further, Fourier imaging is hardly intuitive, and extensive validation of the methods was necessary to ensure that they produced images with sufficient accuracy and fidelity for scientific applications. This book summarizes the results of this development of imaging techniques specifically designed for this form of data. It covers a set of published works that span over two decades, during which various imaging methods were introduced, validated, and applied to observations. Also considering that a new Fourier-based telescope, STIX, is now entering its nominal phase on-board the ESA Solar Orbiter, it became more and more apparent to the authors that it would be a good idea to put together a compendium of these imaging methods and their applications. Hence the book you are now reading.
Download or read book The Impulsive Hard X rays from Solar Flares written by John Leach and published by . This book was released on 1984 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray and Gamma ray Observations of Solar Flares written by Paul Thomas Feffer and published by . This book was released on 1996 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on Hard X ray Emission from Solar Flares and on Cyclotron Radiation from a Cold Magnetoplasma written by Peter Hoyng and published by . This book was released on 1975 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Flare Loops Observations and Interpretations written by Guangli Huang and published by Springer. This book was released on 2018-01-31 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Thermal nonthermal Approach to Solar Flares written by Stephen G. Benka and published by . This book was released on 1991 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Evolution of Energetic Particles and the Emitted Radiation in Solar Flares written by Edward Tsang Lu and published by . This book was released on 1989 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Acceleration and Trapping in Solar Flares written by G. Trottet and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Energetic Phenomena on the Sun written by Mukul Ranjan Kundu and published by . This book was released on 1987 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio and X Ray Evidence for Electron Acceleration in Solar Flares written by R. T. Stewart and published by . This book was released on 1982 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radio and X-ray observations, as well as gamma-ray and interplanetary electron observations, are briefly reviewed for evidence of electron acceleration during solar flares. The evidence suggests that in some large flares a second stage of particle acceleration takes place where ions and electrons are accelerated to very high energies. This second stage follows no more than several minutes after the first or impulsive stage, which occurs during the initial minute or so of the solar flare. During the impulsive phase electrons are accelerated to energies of approximately approx. 10-100 keV, probably by bulk energization, where stored magnetic energy is converted into thermal energy. Energy-loss arguments favor the electrons having a quasi-thermal (near-Maxwellian) electron velocity distribution. During large flares second-phase electrons are accelerated to much higher energies, approx. 10 MeV, and appear to have a power-law velocity distribution. The second-stage acceleration mechanism may be associated with a coronal shock wave, but so far there is no clear evidence that electrons with energies> or = 100 keV are directly associated with a shock wave. (Author).
Download or read book Solar Flares and Coronal Physics Using P OF as a Research Tool written by and published by . This book was released on 1986 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetic Electrons in Impulsive Solar Flares written by David Allen Batchelor and published by . This book was released on 1984 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamic Evolution of the Source Volumes of Gradual and Impulsive Solar Flare Emissions written by and published by . This book was released on 1987 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetics and Dynamics of Simple Impulsive Solar Flares written by and published by . This book was released on 1987 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Hard X ray Microbursts written by Steven Daniel Christe and published by . This book was released on 2007 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Imulsive Phase of Solar Flares written by Joan Welter Vorpahl and published by . This book was released on 1971 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
