Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-27T23:11:22.017Z Has data issue: false hasContentIssue false

Electron Acceleration in Collapsing Magnetic Traps during the Solar Flare on July 19, 2012: Observations and Models

Published online by Cambridge University Press:  24 July 2018

P. A. Gritsyk
Affiliation:
Sternberg Astronomical Institute, Lomonosov Moscow State University, Moscow 119234, Universitetsky pr., 13, Russia email: [email protected]
B. V. Somov
Affiliation:
Sternberg Astronomical Institute, Lomonosov Moscow State University, Moscow 119234, Universitetsky pr., 13, Russia email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Using the appropriate kinetic equation, we considered the problem of propagation of accelerated electrons into the solar corona and chromosphere. Its analytical solution was used for modelling the M7.7 class limb flare occurred on July 19, 2012. Coronal above-the-loop-top hard X-Ray source was interpreted in the thin-target approximation, the foot-point source - in the thick-target approximation with account of the reverse-current electric field. For the foot-point source we found a good accordance with the RHESSI observations. For the coronal source we also got very accurate estimate of the power-law spectral index, but significant differences between the modelled and observed hard X-ray intensities were noticed. The last discrepancy was solved by adding the coronal magnetic trap model to the thin target model. The former one implies that the trap collapses in two dimensions, locks and accelerates particles inside itself. In our report, we confirm an existence and high efficiency of the electron acceleration in collapsing magnetic traps during solar flares. Our new results represent (e.g. for RHESSI observations) the theoretical prediction of the double step particle acceleration in solar flares, when the first step is the acceleration in reconnection area and the second one – the acceleration in coronal trap.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

Bogachev, S. A. & Somov, B. V. 2007, Astron. Lett., 33, 54CrossRefGoogle Scholar
Gritsyk, P. A. & Somov, B. V. 2014, Astron. Lett., 40, 499Google Scholar
Gritsyk, P. A. & Somov, B. V. 2017, Astron. Lett., 43, 614CrossRefGoogle Scholar
Krucker, S. & Battaglia, M. 2014, ApJ, 780, 107Google Scholar
Krucker, S., Battaglia, M., Cargill, P. J., Fletcher, L., Hudson, H. S., MacKinnon, A. L., Masuda, S., Sui, L., et al. 2008, A & AR, 16, 155Google Scholar
Krucker, S., Saint-Hilaire, P., Hudson, H. S., Haberreiter, M., Martinez-Oliveros, J. C., Fivian, M. D., Hurford, G., Kleint, L., et al. 2015, ApJ, 802, 19CrossRefGoogle Scholar
Liu, R. 2013, MNRAS, 434, 1309Google Scholar
Somov, B. V. 2012, Plasma Astrophysics. Part I: Fundamentals and Practice (Springer Science, New York), p. 498Google Scholar
Somov, B. V. 2013, Plasma Astrophysics, Part II: Reconnection and Flares (Springer Science, New York), p. 504Google Scholar
Somov, B. V. & Bogachev, S. A. 2003, Astron. Lett., 29, 621CrossRefGoogle Scholar
Somov, B. V. & Kosugi, T. 1997, ApJ, 485, 859Google Scholar
Somov, B. V. & Syrovatskii, S. I. 1976, Sov. Phys. Usp., 19, 813Google Scholar
Syrovatskii, S. I. & Shmeleva, O. P. 1972, Soviet Astron., 16, 273Google Scholar