1. The impact of magnetic turbulence spectrum on particle acceleration in SNR IC443 I.Telezhinsky 1,2, A.Wilhelm 1,2, R.Brose 1,3, M.Pohl 1,2, B.Humensky 4 Igor Telezhinsky Particle acceleration in IC443 New York, 06.05.2014 1. DESY Zeuthen, Germany 2. University of Potsdam, Institute of Physics & Astronomy, Germany 3. Humboldt University of Berlin, Germany 4. Columbia University, USA

2. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 2 Outline > Particle acceleration  transport equation  diffusion coefficient and turbulence > Magnetic turbulence spectrum  typical view  calculation  first results  approximation > Model of supernova remnant IC443. First results.  (not so) known parameters  modeling  first results > Preliminary conclusions

3. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 3 Particle acceleration: transport equation > Assuming:  CRs scatter elastically  their distribution is isotropic (v CR >> v shock ) > CRs evolution can be described by diffusion-advection equation:  N – energy differential number density of CRs  D – energy dependent diffusion coefficient  u – plasma flow velocity  p t – energy losses  Q – source of thermal particles

4. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 4 Particle acceleration: diffusion coefficient and turbulence > diffusion coefficient, D, defines:  injection of particles from thermal pool  acceleration efficiency (small D  large CR’s residence time  high CR’s E max )  number and spectral shape of escaping particles > escaping particles  produce magnetic turbulence that scatters next generation of injected particles  re-fill Galactic CRs > diffusion coefficient is related to magnetic turbulence > assuming  = const same as E w = const  strong (wrong) assumption

5. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 5 Magnetic turbulence spectrum: typical view I injection II cascading III damping

6. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 6 > Magnetic turbulence spectrum is given by transport equation:  E w – differential (per lnk) energy density of magnetic turbulence relative to background magnetic energy density U  D k – cascading coefficient (Schlickeiser 2002)  u – plasma flow velocity  v a – Alfven velocity   g – resonant mode growth rate (Bell 1978)   d – turbulence damping rate  N – energy differential number density of CRs Magnetic turbulence spectrum: calculation

7. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 7 Magnetic turbulence spectrum: first results Turbulence spectrum Particle spectrum

8. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 8 Magnetic turbulence spectrum: analytic approximation

9. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 9 IC443: wide view Credit: Giovanni Benintende.

10. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 10 IC443: multi-wavelength source, radio/optical G.Castelletti et al. 2011 radio optical both

11. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 11 IC443: multi-wavelength source – x-rays ROSAT (skyview)

12. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 12 IC443: multi-wavelength source – x-rays, HE  -rays ROSAT (skyview) Fermi (skyview)

13. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 13 IC443: multi-wavelength source – x-rays, HE, VHE  -rays ROSAT (skyview) Fermi (skyview) VERITAS (Acciari et al. 2009)

14. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 14 IC443: parameters > type: mixed-morphology  radio shell, center-filled X-rays > age (unclear): 3-30 kyr > distance: 1.5 kpc > size: 45’  20 pc  two hemispheres: R 1 = 7.7 pc, R 2 = 12.1 pc > indications of interaction with dense material  n = 10 -10000 cm -3 > radiative stage of evolution?  slow shocks

15. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 15 IC443: modeling HD and CRs > t = 12500 yr > E SN = 1e51 ergs > n 1 = 12 cm -3  R 1 (t) = 7.7 pc  t tr = 7780 yr, V sh = 0.5V sh (t tr ) = 170km/s > n 2 = 1.9 cm -3  R 2 (t) = 12.1 pc > B 0,1 = ~2e-5 G > B 0,2 = ~6e-6 G > D is calculated from assumed (Kolmogorov) turbulence spectrum > E CR = 0.07 E SN

16. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 16 IC443: modeling emission > Molecular cloud:  d = ~19 pc  size ~ 4.5 pc (~0.16 o )  M MC ~ 1e4-1e5 M Sun > 12 CO image > pion-decay  two SNR hemispheres  dense material illuminated by escaped CRs Lee et al. 2012

17. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 17 IC443: first results – proton spectra

18. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 18 IC443: first results – radiation spectra

19. I.Telezhinsky | Particle acceleration in IC443 | 08.05.2014 | Page 19 Preliminary conclusions > Magnetic turbulence spectrum is not “white noise” > When taken into account, it modifies CR spectrum  downstream of the shock  upstream, at the position of target material > Thorough analysis of dense matter distribution and mass around IC443 is required > Energy dependent morphology and more precise spectral measurements by VERITAS should help constrain model  do we see diffuse emission from denser hemisphere?  is power-law index of hot spot different from “CR sea”?