The 2 Icecube PeV events [A. Schuhkraft@NOW2012 ] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 1 / 23
The 2 Icecube PeV events [A. Schuhkraft@NOW2012 ] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 1 / 23
The 2 Icecube PeV events [A. Schuhkraft@NOW2012 ] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 1 / 23
The 2 Icecube PeV events [A. Schuhkraft@NOW2012 ] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 1 / 23
The 2 Icecube PeV events [A. Schuhkraft@NOW2012 ] Comments: event rate of cosmogenic neutrinos in PeV range is 0 event rate due to Glashow resonance is 0 energies 1.1 PeV and 1.3 PeV below Glashow resonance unlikely cosmogenic, rather diffuse extragalactic flux Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 1 / 23
Acceleration in a Monte Carlo framework Bell s microscopic picture: random walk + advection flow x(t + t) = x(t) + l 0 + v 2 tϑ(r sh r)e r Bohm diffusion: step size l0 = R L energy gain, if shock is crossed ξ = 4 3c (v 2 v 1 ) = v sh /c stop, if t > tmax or r > r esc Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 2 / 23
Acceleration in a Monte Carlo framework Bell s microscopic picture: random walk + advection flow x(t + t) = x(t) + l 0 + v 2 tϑ(r sh r)e r Bohm diffusion: step size l0 = R L energy gain, if shock is crossed ξ = 4 3c (v 2 v 1 ) = v sh /c stop, if t > tmax or r > r esc Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 2 / 23
Acceleration in a Monte Carlo framework Bell s microscopic picture: random walk + advection flow x(t + t) = x(t) + l 0 + v 2 tϑ(r sh r)e r Bohm diffusion: step size l0 = R L energy gain, if shock is crossed ξ = 4 3c (v 2 v 1 ) = v sh /c stop, if t > tmax or r > r esc Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 2 / 23
Acceleration in a Monte Carlo framework Bell s microscopic picture: random walk + advection flow x(t + t) = x(t) + l 0 + v 2 tϑ(r sh r)e r Bohm diffusion: step size l0 = R L energy gain, if shock is crossed ξ = 4 3c (v 2 v 1 ) = v sh /c stop, if t > tmax or r > r esc easy to include: time-dependence of vsh,b,... interactions: production of multi-particle states using e.g. QGSJET Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 2 / 23
Time-dependent framework: Proton flux [MK, Ostapchenko, Tomàs 10, 11 ] 1 model 1 model 2 E 2 F p 10-1 up down total 10-2 10 10 10 11 10 12 10 13 10 14 10 15 E (ev) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 3 / 23
Time-dependent framework: Antiproton ratio F - p / F p+p - 10-4 10-5 10-6 A B A+B 10-7 10 10 10 11 10 12 10 13 10 14 E (ev) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 4 / 23
Time-dependent framework: Antiproton ratio F - p / F p+p - 10-4 10-5 10-6 A B A+B 10-7 10 10 10 11 10 12 10 13 10 14 E (ev) component A: p produced in acceleration zone; component B: p produced downstream Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 4 / 23
Time-dependent framework: Antiproton ratio F - p / F p+p - 10-4 10-5 10-6 A B A+B 10-7 10 10 10 11 10 12 10 13 10 14 E (ev) component A: p produced in acceleration zone; component B: p produced downstream A is flatter: dn/de(a) E 1 but dn/de(a + B) E 2 Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 4 / 23
Antimatter ratios from SNRs [MK, Ostapchenko, Tomàs 10, 11 ] F x - / F x+x - 10-1 10-2 10-3 10-4 10-5 10-6 e + /(e + +e - ) model 1 model 2 p/(p+p) - - 10 10 10 11 10 12 10 13 10 14 E (ev) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 5 / 23
(Hadronic) Photons and neutrinos from Tycho: p 2 J(p) [TeV m -2 s -1 ] 6 5 4 3 2 gammas neutrinos 1 8 9 10 11 12 13 14 15 16 E [ev] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 6 / 23
(Hadronic) Photons and neutrinos from Tycho: p 2 J(p) [TeV m -2 s -1 ] 6 5 4 3 2 gammas neutrinos 1 8 9 10 11 12 13 14 15 16 E [ev] SNR produce neutrinos with energies up to PeV I γ (E) I ν (E) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 6 / 23
Tycho observations by VERITAS Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 7 / 23
CR diffusion close to source, E = 10PeV, t = 2000yr S 0 0.2 0.4 0.6 0.8 1 Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 8 / 23
CR diffusion close to source, E = 10PeV, t = 7000yr S Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 8 / 23
CR diffusion close to source, E = 10PeV, t = 500yr S Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 8 / 23
Filamentary CR diffusion close to source: [Giacinti, MK, Semikoz 12 ] Explanation: CRs scatter on modes with kr L 1 fast modes with kr L 1: irrelevant slow modes with kr L 1: act as regular, uniform field B 0 propagation along B 0 is faster than perpendicular Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 9 / 23
Filamentary CR diffusion close to source: [Giacinti, MK, Semikoz 12 ] Explanation: CRs scatter on modes with kr L 1 fast modes with kr L 1: irrelevant slow modes with kr L 1: act as regular, uniform field B 0 propagation along B 0 is faster than perpendicular Why not seen earlier in simulations? too large scales, l l max, considered anisotropy vanishes averaging over field realizations anisotropy vanishes for random start positions Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 9 / 23
E = 100 TeV 1 PeV 10 PeV t = 500 yr 2000 yr 7000 yr S S S S S S S S S 0 Michael Kachelrieß (NTNU Trondheim) 0.2 0.4 0.6 Cosmic Rays 0.8 1 IPM School, Tehran 2012 10 / 23
Calculation of diffusion tensor: inject N particles at x = 0 in one single realization b Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 11 / 23
Calculation of diffusion tensor: inject N particles at x = 0 in one single realization b calculate D (b) ij = 1 N N a=1 x (a) i x (a) j 2t Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 11 / 23
Calculation of diffusion tensor: inject N particles at x = 0 in one single realization b calculate D (b) ij = 1 N N a=1 x (a) i x (a) j 2t diagonalizes D (b) ij, determine eigenvalues d(b) i Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 11 / 23
Calculation of diffusion tensor: inject N particles at x = 0 in one single realization b calculate D (b) ij = 1 N N a=1 x (a) i x (a) j 2t diagonalizes D (b) ij, determine eigenvalues d(b) i average the ordered eigenvalues, d (b) 1 < d (b) 2 < d (b) 3, over the M realizations, d i = 1 M d (b) i M b=1 Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 11 / 23
Eigenvalues of D ij = x i x j /(2t) for E = 10 15 ev D(1PeV) (cm 2 /s) 1e+29 1e+28 d 3 d 2 d 1D 0.1 1 10 100 Time (kyr) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 12 / 23
Eigenvalues of D ij = x i x j /(2t) for E = 10 15 ev D(1PeV) (cm 2 /s) 1e+29 1e+28 d 3 d 2 d 1D 0.1 1 10 100 Time (kyr) asymptotic value is 4 smaller than Galprop value Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 13 / 23
Transition time to standard diffusion: 1e+30 1e+30 1e+30 D(10PeV) (cm 2 /s) 1e+29 1e+29 1e+28 (b) d 1e+28 3 (b) d 2 (b) d 1 1e+27 1e+27 D (b) 0.1 1 10 0.1 1 10 Time (kyr) Time (kyr) D(1PeV) (cm 2 /s) D(100TeV) (cm 2 /s) 1e+29 1e+28 1e+27 0.1 1 10 Time (kyr) t 10 4 yrs (l max /150 pc) β (E/1 PeV) γ with β 2 and γ = 0.25 0.5 for Kolmogorov turbulence and B rms = 4µG. Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 14 / 23
Comparison CR density vs. photon flux 10 10 5 5 0 0-5 -5-10 -10-5 0 5 10 0.01 0.1 1-10 -10-5 0 5 10 0.01 0.1 1 irregular gamma-ray halos as tracker of CR density Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 15 / 23
Average intensity I(E) of Galactic CRs precise measurements by PAMELA, soon AMS-02 Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 16 / 23
Average intensity I(E) of Galactic CRs precise measurements by PAMELA, soon AMS-02 local measurements I(x, E) may deviate from average: solar wind local sources Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 16 / 23
Average intensity I(E) of Galactic CRs precise measurements by PAMELA, soon AMS-02 local measurements I(x, E) may deviate from average: solar wind local sources reconstruct I(E) using gamma-rays from molecular clouds, dn γ de γ Emax E γ de dn CR de dσ pp γ (E, E γ ) de γ Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 16 / 23
Average intensity I(E) of Galactic CRs precise measurements by PAMELA, soon AMS-02 local measurements I(x, E) may deviate from average: solar wind local sources reconstruct I(E) using gamma-rays from molecular clouds, dn γ de γ Emax E γ de dn CR de dσ pp γ (E, E γ ) de γ ill-posed problem, fit instead physically motivated trial functions (broken) power-laws Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 16 / 23
Neronov, Semikoz and Taylor 2012: single power-law I(T) T α does not reproduce 2 GeV break of I γ Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 17 / 23
Neronov, Semikoz and Taylor 2012: single power-law I(T) T α does not reproduce 2 GeV break of I γ best-fit: broken power-law in T, breaks at 10 and 200 GeV Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 17 / 23
Neronov, Semikoz and Taylor 2012: single power-law I(T) T α does not reproduce 2 GeV break of I γ best-fit: broken power-law in T, breaks at 10 and 200 GeV physical explanation? 200 GeV: end of solar modulation 10 GeV: change in D(E) [Blasi, Amato, Serpico 12 ] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 17 / 23
How good are photon FF? QGSJET vs. SIBYLL [MK, Ostapchenko 12 ] π -1 x E dσ/dx F (mb) 10 2 10 1 p + p π 0 at 400 GeV/c π -1 x E dσ/dx F (mb) 10 1 p + p η at 400 GeV/c 10-1 10-1 10-2 10-2 10-3 0 0.2 0.4 0.6 0.8 1 x F 0 0.2 0.4 0.6 0.8 1 x F Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 18 / 23
How good are photon FF? QGSJET, SIBYLL, Kamae E γ dσ/de γ (mb) 10 2 p + p γ at 50 GeV p + p γ at 5 TeV p + p γ at 500 TeV 10 1 0 0.2 0.4 0 0.2 0.4 0 0.2 0.4 x E x E x E Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 19 / 23
How good are Fragmentation Functions? there are differences: we recommend http://sourceforge.net/projects/ppfrag Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 20 / 23
How good are Fragmentation Functions? there are differences: we recommend http://sourceforge.net/projects/ppfrag Kamae FF used by NST works well up 50 GeV Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 20 / 23
How good are Fragmentation Functions? there are differences: we recommend http://sourceforge.net/projects/ppfrag Kamae FF used by NST works well up 50 GeV in integrated results spectral differences washed out E γ 2 dn γ /de γ (rel. units) 0.9 1 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 1 10 10 2 10 3 10 4 E γ (GeV) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 20 / 23
How good are Fragmentation Functions? there are differences: we recommend http://sourceforge.net/projects/ppfrag Kamae FF used by NST works well up 50 GeV in integrated results spectral differences washed out E γ 2 dn γ /de γ (rel. units) 0.9 1 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 1 10 10 2 10 3 10 4 E γ (GeV) Kamae FF not reason for bump Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 20 / 23
Gammas from CR power-laws in T vs. p 1 0.1 E_kin-spectrum p_lab-spectrum E_lab-spectrum 0.01 0.001 0.0001 1e-05 1e-06 0.1 1 10 100 1000 10000 Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 21 / 23
Gammas from CR power-laws in T vs. p 1 0.1 E_kin-spectrum p_lab-spectrum E_lab-spectrum 0.01 0.001 0.0001 1e-05 1e-06 0.1 1 10 100 1000 10000 most of the bump comes from power-law in T DSA predicts power-law in p [Bell 77 ] Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 21 / 23
Gammas from CR power-laws in T vs. p 0.0001 E 2 Flux [GeV/cm 2 s] 1e-05 0.1 1 10 100 E [GeV] red: I p 2.85 (our FF) blue: I p 2.85, break to I p 1 at 3 GeV (our FF) Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 22 / 23
Gammas from CR power-laws in T vs. p 0.0001 E 2 Flux [GeV/cm 2 s] 1e-05 0.1 1 10 100 E [GeV] red: I p 2.85 (our FF) blue: I p 2.85, break to I p 1 at 3 GeV (our FF) explanation: break in D(E) around 3 GeV as suggested by radio data caused by CR damping standard solar modulation Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 22 / 23
Summary Intensity I(p) of sea CRs important for CR physics, DM searches. determination via GMC requires additional input controversial solutions minimal: power-law in I(p) supports DSA, consistent with standard solar modulations, break 3 GeV Anisotropic diffusion on scales l < l max leads to irregular CR and gamma halos Icecube events: consistency between diffuse νµ and cosmogenic analysis unlikely cosmogenic, rather diffuse extragalactic flux; galactic possible? Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 23 / 23
Summary Intensity I(p) of sea CRs important for CR physics, DM searches. determination via GMC requires additional input controversial solutions minimal: power-law in I(p) supports DSA, consistent with standard solar modulations, break 3 GeV Anisotropic diffusion on scales l < l max leads to irregular CR and gamma halos Icecube events: consistency between diffuse νµ and cosmogenic analysis unlikely cosmogenic, rather diffuse extragalactic flux; galactic possible? Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 23 / 23
Summary Intensity I(p) of sea CRs important for CR physics, DM searches. determination via GMC requires additional input controversial solutions minimal: power-law in I(p) supports DSA, consistent with standard solar modulations, break 3 GeV Anisotropic diffusion on scales l < l max leads to irregular CR and gamma halos Icecube events: consistency between diffuse νµ and cosmogenic analysis unlikely cosmogenic, rather diffuse extragalactic flux; galactic possible? Michael Kachelrieß (NTNU Trondheim) Cosmic Rays IPM School, Tehran 2012 23 / 23