High-Energy Aspects of Solar Flares: Overview of the Volume

In this introductory chapter, we provide a brief summary of the successes and remaining challenges in understanding the solar flare phenomenon and its attendant implications for particle acceleration mechanisms in astrophysical plasmas. We also provide a brief overview of the contents of the other chapters in this volume, with particular reference to the well-observed flare of 2002 July 23Comment: This is the introductory article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

Directionality of solar flare-accelerated protons and alpha -particles from gamma -ray line measurements

Théori

Spectral evolution in gamma-ray bursts

The Hard X-ray Burst Spectrometer (HXRBS) and the Gamma-Ray Spectrometer (GRS) on NASA's Solar Maximum Mission satellite (SMM) have independently monitored cosmic gamma-ray bursts since launch in February 1980. Several bursts with relatively simple pulse structure and sufficient intensity have been analyzed for evidence of spectral variability on timescales shorter than the pulse durations. In many of these bursts we find pulse structures, ranging in duration from 1 to 10 seconds, which exhibit a trend of hard-to-soft spectral evolution. No significant evidence for soft-to-hard evolution has been found, although the possibility of weak, extended low-energy emission is suggested in a few bursts. The HXRBS data above 100 keV and the GRS data above 1 MeV indicate that the spectral evolution generally is not due to time-varying absorption features at energies below 100 keV. © 1986

Evidence for a 154 day periodicity in the occurrence of hard solar flares

To be published in NATURESIGLETIB: RN 9303 (27) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman