Issue |
A&A
Volume 612, April 2018
|
|
---|---|---|
Article Number | A64 | |
Number of page(s) | 10 | |
Section | The Sun | |
DOI | https://doi.org/10.1051/0004-6361/201730708 | |
Published online | 25 April 2018 |
Spatially inhomogeneous acceleration of electrons in solar flares
1
School of Physics and Astronomy, University of Glasgow,
Kelvin Building,
Glasgow
G12 8QQ, UK
2
King’s College London,
Strand,
London
WC2R 2LS, UK
e-mail: duncan.stackhouse@kcl.ac.uk
Received:
27
February
2017
Accepted:
21
December
2017
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 that the energisation of these particles takes place over a region of finite size, sometimes resolved by RHESSI observations. In this paper, we present, for the first time, a spatially distributed acceleration model and investigate the role of inhomogeneous acceleration on the observed X-ray emission properties. We have modelled transport explicitly examining scatter-free and diffusive transport within the acceleration region and compare with the analytic leaky-box solution. The results show the importance of including this spatial variation when modelling electron acceleration in solar flares. The presence of an inhomogeneous, extended acceleration region produces a spectral index that is, in most cases, different from the simple leaky-box prediction. In particular, it results in a generally softer spectral index than predicted by the leaky-box solution, for both scatter-free and diffusive transport, and thus should be taken into account when modelling stochastic acceleration in solar flares.
Key words: Sun: flares / Sun: corona / Sun: X-rays, gamma rays
© ESO 2018
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.