4. Traditional image of the CR energy spectrum
( knee )
( ankle )

5. Sharpness and fine structure of the spectrum in the knee region
2001, Ch
2001, Ne
2010, E0

6. not observed
in 2006
me, Baksan
me, SYB zm
me, QGS mh
mhe

7. GAMMA

9. KASCADE - Grande

10. Ice-Top
single power law

11. Fine structure of the CR energy spectrum
in the tens PeV region beyond the knee includes:
* flattening of the spectrum above 20 PeV ;
* possible ‘bump’ at 50 – 80 PeV;
* steepening above 100 PeV.

12. Anatomy of the knee
The fine structure can be due to the non-uniformity of the space-time distribution of CR sources with the dominant contribution of nearby and recent sources
( SNR, pulsars ). In the Single Source Model of the knee
the total intensity consists of the contributions from the
dominant single source and background of multiple sources.
Here we estimate the contribution of ‘plural’ sources - not very old and distant, but not as strong as the dominant single source. We analysed the contribution of the second strong source and the ratio S2/S1.

13. Simulated energy spectra of cosmic rays
for non-uniform space-time distribution of SNR
What are S2/S1
here ?

14. Distribution of S2/S1 ratio
P(>0.2)=0.08

15. Estimates of the contribution from the real nearby and recent sources

16. List of 24 nearby and recent sources: R<1.5kpc,T<120kyear
( Sveshnikova L.G. et al., 2011 )

17. CR energy spectra from several nearby and recent SNR

18. We conclude that the contribution
to the knee of a few ‘plural’ sources
does not exceed ~10%

19. Energy spectrum and mass composition of cosmic rays from the single source and Vela pulsar
(Fe)

20. Fine structure at sub-TeV energies
There is a concavity of the energy spectrum
of all major CR components at hundreds GeV
( ‘ankle’ at ~200 GeV/nucleon ).
Experiments: ATIC, CREAM, PAMELA

21. P & He

22. O, Mg & Fe

23. Concavity quantified by the ‘sagitta’

24. Sagittas in simulations and in the experiment

25. Observed curvature can be hardly
explained by the random geometric
configuration of cosmic ray sources

26. Search and the study of the fine structure
of the spectrum can be an additional source of information on the nature and
origin of CR in the studied energy region

27. THANK YOU !