1. Recent results in cosmic ray physics and their interpretation
Author: Blasi, P.
arXiv:
reported by Zhang Xiao

2. Outline 1. Introduction 2. Status of the SNR paradigm
3. Spectral breaks
4. CR acceleration in partially ionized media
and Balmer line emission in SNRs
5. summary

3. 1. Introduction

4. 2. Status of the SNR paradigm
particles are accelerated at SNR with spectral index of α
E dependent diffusive propagation with
observed CRs with spectral index α + δ ~ 2.7
δ = 0.7 ?
the test particle theory of particle acceleration: α = 2
anisotropy

5. 2. Status of the SNR paradigm
standard DSA
efficient
predictions of NLDSA:
1. concave-shap spectrum
2. decrease the T of downstream gas
3. CR-induced plasma instabilities

6. 2. Status of the SNR paradigm
Escaping
When, How

7. 2. Status of the SNR paradigm
◆ B-field amplification
Why ?
1. to explain the thin nonthermal X-ray rims in virtually all young SNRs.
2. let maximum energy close to the knee energy.
How ?
1. due to plasma related phenomena if the shock propagates in an inhomogeneous medium.
2. CR-induced magnetic field amplification

8. 2. Status of the SNR paradigm
◆ test of the SNR paradigm: gamma-rays emission
I) the SNR-MCs system
II) the young individual SNRs
example: RX J and Tycho

9. 3. Spectral breaks ◆ Observed results PAMELA and CREAM Proton
80GV < Ф < 232 GV
α: 2.85 ± ± 0.004
Ф > 232 GV
α: 2.67 ± 0.03 ± 0.05
Helium
80GV < Ф < 240 GV
α: ± 0.01±0.027
Ф > 240 GV
α: 2.477±0.06±0.03
Adriani, O. et al. 2011, Sci, 332, 69

10. 3. Spectral breaks
1. both spectra have a break at rigidity ~ GV
2. the spectrum of He is systematically harder than the p spectrum.
● not confirmed by AMS-02 !
● supported by the analysis of the gamma ray spectrum
of gamma rays from MCs in the Gould belt.
confirmed by AMS-02

11. 4. dispersion in the spectral indices
3. Spectral breaks
Interpretation:
1. local source
Thoudam and Horandel 2012, MNRAS, 421, 1209
Thoudam and Horandel arXiv
2. NLDSA at FS and RS
Ptuskin et al, 2013, ApJ, 763, 5
3. propagation effects
I) D(E) → D(x, E)
Tomassetti, T. 2012, ApJL, 752, L13
II) pre-existing turbulence + self-generated turbulence
Blasi, p. et al, 2012, SPhReL, 109, 61
4. dispersion in the spectral indices
Yuan et al. 2011, PhReD, 84,

12. 4. CR acceleration in partially ionized media
and Balmer line emission in SNRs
◆ Balmer line emission
collisionless shock
upstream
downstream
ionized hydrogen with low T + +
ionized hydrogen with high T +
neutral hydrogen with low T
neutral hydrogen with high T
T ↑ T→ +
exchange e-
broad Balmer line
narrow Balmer line

13. 4. CR acceleration in partially ionized media
and Balmer line emission in SNRs
◆ Balmer line emission
collisionless shock
upstream
downstream
ionized hydrogen with low T + +
ionized hydrogen with high T +
neutral hydrogen with low T
neutral hydrogen with high T
T ↑ T→ +
exchange e-
broad Balmer line
narrow Balmer line
New phenomena under the condition of efficient acceleration
1. decrease the T of the
gas downstream
2. A precursor is formed
upstream
narrow the broad Balmer line
broaden the narrow Balmer line

14. 4. CR acceleration in partially ionized media
and Balmer line emission in SNRs
◆ Shape of the Balmer line emission

15. 4. CR acceleration in partially ionized media
and Balmer line emission in SNRs
◆ Modification caused by neutral gas
collisionless shock
upstream
downstream +
neutral return flux !
reduce Mach number
intermediate Balmer line

16. 4. CR acceleration in partially ionized media
and Balmer line emission in SNRs
◆ Example: SNR

17. Thank You !

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