High-energy processes in solar flares: gamma-ray and sub-mm insights

• Grant number: 13/04248-7
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Duration: September 24, 2013 - December 23, 2013
• Field of knowledge: Physical Sciences and Mathematics - Physics - Physics of Fluids, Plasma Physics and Electrical Discharge
• Principal Investigator: Pierre Kaufmann
• Grantee: Pierre Kaufmann
• Visiting researcher: Alexander Lachlan Mackinnon
• Visiting researcher institution: University of Glasgow, Scotland
• Host Institution: Escola de Engenharia (EE). Universidade Presbiteriana Mackenzie (UPM). Instituto Presbiteriano Mackenzie. São Paulo , SP, Brazil
• Associated research grant: 06/06847-1 - Solar activity emissions from submillimeter waves to infrared (SIRA), AP.TEM

Abstract

Solar flares offer a detailed look at an astrophysical site of particle acceleration, where energy initially stored in stressed magnetic fields is somehow converted rapidly into particles (electrons and ions) with energies far above the thermal energy. Recent years have seen major advances in the study of gamma-rays and sub-mm radiation from these events, the latter due primarily to the efforts of Kaufmann (Mackenzie University) and his collaborators so that Brazil is the obvious location in the world for serious studies of these topics. Both wavelength ranges have information to offer on the highest energy particles produced in flares and instrumental technology is now advancing to the point where this can be exploited. Here we propose to carry out theoretical studies of flare fast ion transport and nuclear processes to identify how sub-mm and gamma-ray measurements together may yield new, detailed information on ion acceleration in flares. We will make predictions of the spatial structure of the sub-mm radiation produced by secondaries of fast ions and evaluate how ALMA may be used to determine properties of ion acceleration in flares. We will determine if the long-lasting gamma-ray continuum recently observed by the NASA Fermi mission can have observable correlates in the sub-mm range, and what extra information these would yield on the long-lasting ion acceleration process. Millimetre and now sub-mm observations of flares open a window on the fragmentation of flare energy release, whose full significance we will explore using methods from fluid turbulence theory. (AU)