Ryo Yamazaki(Aoyama Gakuin University)(With T. Inoue, Y. Ohira, S. Inutsuka, Y. Fukui)

Similarities between us and “SN” people
Our claim:
Multi-dimensional model is necessary to fully understandcosmic ray acceleration.
Importance of inhomogeneity of circumstellar material andmulti-dimensionality effects.
However, quantitative discussion is difficult, because it’s hard tosolve kinetic equation describing CR transport in multi-D models.
 In this talk, I present qualitative arguments.
Quantitative arguments coming soon?

Open Questions in CR community
Is the supernova remnant (SNR) really “proton” accelerators ?
(We have already known from synchrotron radio-X-ray emissions
that “electrons” are accelerated at SNR.)
If the answer is “yes”, thena) How large is the maximum CR proton energy?
Measured CR spectrum implies Emax~1015.5eV.
b) How much energy of SN explosion goes into CR protons?
Measured CR flux implies 1~10%.
=> Gamma-ray and X-ray observations play important roles.

F [erg s-1 cm-2]

Wide-band -ray spectra of SNRs
S.Funk (2011)F [erg s-1 cm-2]

Wide-band -ray spectra of SNRs
S.Funk (2011)

RX J1713.7‐3946

H.E.S.S.

Spectrum of RX J1713.7-3946
Observed spectrum (Fermi LAT) : F ∝  If -rays are “electron” origin (IC),F ∝ (3-p)/2 ∝   => p = 2.0
If -rays are “proton” origin (decay of ),F ∝ 2-p ∝   => p = 1.5

F [erg s-1 cm-2]

Abdo et al. 2011

H.E.S.S.

F∝  

Spectrum of RX J1713.7-3946
Observed spectrum (Fermi LAT) : F ∝  If -rays are “electron” origin (IC),Just right a prediction(3-p)/2F ∝ ∝=> p = 2.0of Fermi accelerationIf -rays are “proton” origin (decay of  ),F ∝ 2-p ∝   => p = 1.5 theory.

F [erg s-1 cm-2]

Abdo et al. 2011

H.E.S.S.

F∝  Non-detection of X-ray lines
X-rays from RX J1713

Ellison + 10:“Proton” model overpredicts
thermal X-ray lines in order
to fit the gamma-ray flux
with pi^0 decay process.
→ prefers “electron” model.

F [erg s-1 cm-2]

purely non-thermal(that is synchrotron radiation
From ~ 1-10 TeV electrons):
Dim (non-detected) thermal
X-ray lines.

(Proton)(Electron)If -rays are electron-IC, then B~10 GPower of synch. radiation

Power of IC emission

F [erg/s/cm2]

X-ray
TeVSynchrotron
IC/CMBfor CMB backgroundB ~10G from observed ratio, “Psyn/ PIC ~ 10”.

B~mG at RX J1713.7-3946 ?
Synch. X‐ray image

TeV‐

H.E.S.S.

Uchiyama et al. ‘07

B~mG at RX J1713.7-3946 ?
Synch. X‐ray imageTeV‐Time-variable
synchrotron X-rays observed!!
If synch. cooling time ~1yr, B~mG is indicated.
( for X-ray emitting electrons, tsynch~1.5(B/mG)-1.5yr )H.E.S.S.

Uchiyama et al. ‘07

Problems on RXJ1713
If gamma-rays are leptonic (“electron” origin)…

* Magnetic field ~ 10 G is much smaller than expected?
=> We need different interpretation of thin X-ray filamentand X-ray time variability?

If gamma-rays are hadronic (“proton” origin)…
* too hard GeV-TeV spectral slope (F ∝   p ~1.5 ? )* predicted X-ray lines too bright.
* e/p ratio ~10-5 , much smaller than measured at Earth.

A possible solution (Inoue, RY+2012)
If SN explosion occurs in the inhomogeneous environment,“proton” model may explain all observational results.
← environment justbefore SN explosion:
wind cavity (bubble),& dense clouds.

Inoue, RY+2012

A possible solution (Inoue, RY+2012)
Indeed, RX J1713.7-3946 is embedded in highly
inhomogeneous medium.

Color: 1-5 keV (Suzaku) = Synchrotron X-rays
Contour: 12CO(J=2-1) (NANTEN) = Molecular clouds

Sano, RY et al. (2013)

A possible solution (Inoue, RY+2012)
3D MHD simulation shows that the shock-cloud interaction
generates vorticity around which magnetic field is amplified.
Structure of |B|

Structure of nzz

yyx
Blue : shocked cloudOrange : shocked diffuse gasx
Blue : 10 G < |B| < 100 G
Green : 100 G < |B| < 500 G
Red : 500 G < |B|Result of MHD simulation
Magnetic Field is amplified via turbulent dynamo.
Density log (n)Field Strength |B|Inoue, RY, Inutsuka 09

A possible solution (Inoue, RY+2012)* Dim thermal X-ray lines:
・shocked wind (n~0.01)=> low density.
・shocked cloud (n~103)=> low shock velocity=> low temperature.

Forward
ShockCloudB ~ mGp* Gamma-ray spectrum:
high-energy protons (produced in thediffuse gas region) hit clouds.
penetration length: L ∝ (Dt)1/2 ∝ E0.5 ∝  => F ∝  p-2 × L ∝   (for p = 2.0)
(observed “electron-IC-like” spectral slope!!)SummaryIf SN explosion occurs in the inhomogeneous environment,hadronic model (in which gamma-rays are proton origin)may not contradict observational results.
More quantitative arguments are under investigation.
Reference:
Inoue et al. ApJ, 744, 71 (2012)
Others:Inoue et al. ApJL, 723, L108 (2010), ApJ, 695, 825 (2009)
Yamazaki et al. A&A, 495, 9 (2009)

Neutrino observation will answer the problem?

F [erg s-1 cm-2]

KM3NeT-neutrinos

RY+(‘09)-decay
Gamma-rays