1. On the Spectral Components of the June 2000 Solar Energetic Particle Events J. Torsti, J. Laivola, P. Mäkelä, I-V. Lehtinen and O. Saloniemi Space Research Laboratory, University of Turku
Kiel, August 2006

2. Outline The period of high Solar activity in June 2000
Motivation behind the study
Fitting of the (event integrated) spectra and results
The events, piece by piece
Summary & future work

3. June 2000, ERNE protons
The time intensity profiles of the events were typical to far-eastern, moderate eastern and western events, Cane et al. (1988).
3(/4) SEP events, 13 X-ray flares, 9 CMEs

4. GOES X-ray flares
9026
MDI :51
LASCO CMEs
9031

5. Motivation behind the studyp He
Events:
I = Jun 10
II = Jun 06
III = Jun 03
Intensity*(E/10)3.5
None of the observed (proton) spectra can be fitted with a single, well-known form of power-law with exponential cut-off

6. Fitting
Complicated observational spectra  Fitting could be done only after dividing the whole energy range into pieces
Power law with exponential turnover
Double power law
Modified Bessel function of the second kind
Exponential in rigidity
No significant differences between the different forms
Power law with exponential turnover chosen
Käytetty fittaustyökalu…
Ellison, D. C. and Ramaty, R. 1985, Astrophysical Journal, 298, 400
Mewaldt, et al. 2005, Journal of Geophysical Research (Space Physics), 110:9–.
Forman, M. A., et al. 1986, Physics of the Sun. Volume 2, pages 249–289.

7. Formulas ”Single ER” ”Double ER” ”Triple ER”
Ellison, D. C. and Ramaty, R. 1985, Astrophysical Journal, 298, 400

8. Protons (whole event) Jun 3 Jun 10 – Single ER fit – Double ER fit
Sorry, no 3x ER fit and no multiplier by 3.5…
– Single ER fit
– Double ER fit
Jun 6

9. Oxygen (whole event) Jun 3 Jun 6 Jun 10 – Single ER fit
Jun 6: transition region between LED and HED (large errors)
– Single ER fit
– Double ER fit

10. Best fit (2) He p ~30 points 3 – 9 free params Protons He Event
Single
Double
Triple
Jun 3
Jun 6
Jun 10
~30 points
3 – 9 free params He
The relative error of the spectral points is quite low except the high energy range which justifies to test also a three-component model. p

11. Best fit parameters
Problems!!!

12. Evolution of proton spectra (1)
Jun 3
6 h/period
6 h period, arrow points the direction of spectral evolution, a and b artificially selected

13. Evolution of proton spectra (2)
Jun 6
3 h/period

14. Evolution of proton spectra (3)
Jun 10
3 h/period

15. Time development of the parameters (1)
Jun 3, single ER vs. double ER
2 A g E0

16. Time development of the parameters (2)
Jun 6, double ER vs. triple ER
2
Problems with fitting… A g E0

17. Time development of the parameters (3)
Jun 10, double ER vs. triple ER
2 A g E0

18. Summary
The beginning of June 2000 provides an excellent opportunity to study particle acceleration and source populations
3 (4) SEP events, 13 X-ray flares, 9 CMEs
Single power-law with exponential cut-off doesn’t provide suitable fits for June 3, 6 and 10 events
June 3  single/double ER?
June 6 / June 10  double/triple ER?
Statistics limit the evaluation of He and heavier ions, however 2 components can be seen in oxygen spectra of June 6 event

19. Future work
Improve the fitting of 3/6 h spectra periods (maybe try different fitting software)
Evaluate how realistic the fitting results are (do we really need three components? Or two?)
Try to find the physics behind the spectral components, the origin of each component?