Astroparticle yield in radio galaxies jets and hot spots

1
Astroparticle yield in radio galaxies jets and
hot spots

• A.Marcowith (C.E.S.R. Toulouse France)
• F.Casse (F.O.M. Rijnhuizen, the Netherlands
  A.P.C. Paris, France)

2
Outline

• Multi-? high spatial resolution observations.
• Methodology MHD-SDE code.
• Jets hot spots
• - Particle transport in complex flows
• - Microscopic turbulence
• - Astroparticle yield
• Future works.

3
Multi-? observations

• Multi-wavelength spectra
• High resolution maps (VLBI, HST, Chandra
  XMM-Newton).
• ? Spectral and spatial analysis
• Supernova remnants (van der Swaluw Achterberg
  2004)
• Massive star formation sites (poster on
  Super-bubbles)
• Active Galactic Nuclei jets and hot spots (this
  talk)

4
Radio-X-ray jets
IC/CMB ?
synchrotron
Sambruna et al. 2002
1 5.4 kpc
5
FRII hot spots
Hot spot A
Wilson et al. 2000
core
jets
Chandra
Cygnus A (VLA 5 GHz )
SSC
FR Fanaroff Riley radio-galaxies FRII are the
most powerful RG.
6
Astrophysical interests

• Radiative processes in high energy sources
• - Origin of the X-ray radiation in jets and
  hot spots
• Relativistic particle production, acceleration
  and propagation
• - Cosmic-ray physics.
• Constraints on transport processes
• - Turbulence (fluid microscopic), magnetic
  field configuration, link to macroscopic
  structures.

Need for multi-scale computational methods
linking large MHD scale to kinetic transport ...
7
Multi-scale simulation

• (3Dtime) MHD kinetic Eq. radiative
  processes.
• MHD Versatile Advection Code (www.physics.uu.nl/
  toth)
• - 3D conservative schemes non-relativistic
  flows
• Kinetic equations Diffusive approximation
• - Stochastic differential equations ?
  Diffusion-convection equation
• Radiative processes synchrotron/IC losses (e-),
  hadronic interaction (p-p, p-? gamma-ray
  neutrino)

8
Diffusive shock acceleration

• Constraints on ?tsde and ?

?Xadv
upstream
downstream
?Xdiff
?Xshock
ideal sharp discontinuity
Numerical smoothing over few grid cells
Necessary condition to compute the shock process
correctly ?Xadv ( Vflow ?tsde) lt ?Xshock lt
?Xdiff ( v2 ? ?tsde) (Kruells Achterberg 1994
N Dim. extension Casse Marcowith 2003) ?
?tsde and ?min
9
SDEs

• 3D axisymetric MHD ? Vflow, B, tMHD.
• Microscopic turbulence model ? diffusion
  coefficients ?.
• Sum number of particles N(p,t) in a given (r,z) ?
  distribution function at tMHD.

10
Extragalactic jets hot spots

• FRI jets (Casse Marcowith AA 2003)
• Complex shock structures.
• Multiple-shock acceleration.
• Hot spots (Casse Marcowith PRD 2004 sub.)
• Constraints on turbulence regime.
• Magnetic field configuration.
• Astroparticle yield (gamma-rays, high energy
  neutrinos, cosmic-rays).

11
Complex shock structure
Kelvin-Helmoltz instability ? internal shocks in
jet T1 (weak curved shock lt r gt 2.76)
lt T2 (strong planar shock lt r gt 4)
Stationary sol. F(p) ? p-3r/(r-1)
12
Hot spot simulation
Poloidal MF
AMR-VAC (Keppens 2004)
13
Astroparticle yield in HS
Cygnus A Electrons
Cygnus A protons
At the terminal shock
Over the HS
synchrotron
zoom
Proton Escaping the HS
At the terminal shock
Kolmogorov turbulence poloidal MF Ecr max
fixed by escape losses ? transport
Ecrmax 5 x 1016 eV
14
3C273A electrons
3C273A protons
At the terminal shock
Over the whole HS
At the terminal shock
synchrotron
zoom
Escaping protons
Kolmogorov turbulence toroidal MF
Ecrmax 7 x 1019 eV
15
E-2 spectrum
Secondaries from 3C273A

• Neutrinos flux on Earth 2.3 x 10-14 GeV / cm2 s
  sr ( 5 orders of magnitude under ANTARES
  sensitivity)
• p-p gamma-ray flux on Earth 4.7 x 10-14 GeV /
  cm2 s sr ( 3 orders of magnitude under GLAST
  sensitivity)

16
Conclusions

• Methodology
• Multi-? high resolution observations ?
  multi-scale simulations to handle
• gt Macroscopic structures.
• gt Microscopic physics.
• Mesoscopic simulation schemes MHD-EDS
• Easy to implement, able to handle complex
  flows configurations with shocks.
• - Statistics, test-particle approximation.
• Other methods do exist (T. Downes et al. 2002,
  T. Jones et al. 1999, A. Micono et al. 1999)

17

• Astrophysics Jets Hot spots
• Investigate complex shock structure in jets and
  hot spots
• Constraints on acceleration mechanisms or
  turbulence
• Multi-? spectra astroparticle
• 3C273A (transverse shock acceleration high
  synchrotron cut-off 1014 Hz)

18
Future works

• Full time-dependent simulation for FRI jets
• X-ray dominated synchrotron astroparticle
  production (FRI some hot spots)
• Multi-wavelength maps
• Other objects (SNr,SNr-cloud interaction,
  colliding stellar winds...)
• Extension to relativistic flows (FRII
  radio-galaxies)
• Make time dependent SDEs available for the
  community and insert an SDE routine in VAC and
  AMR-VAC.

19
Multiple shock effects
Test particle approximation theory p F(p) ?
p-(tacc/tesc) Multiple shock with no escape ?
flat p F(p) distribution
Synchrotron losses

• Spectral energy distribution without synchrotron
  losses for
• Const. Diff. Coeff.
• Kolmogorov with ? turbulence level

20
MHD turbulence in HS

• Test // and ? shocks (poloidal or toroidal MF
  dominated HS)
• Test different transport theory
• Isotropic Kolmogorov, Kraichnan, Bohm.
• Anisotropic Goldreich-Sridhar
• Main conclusions
• Highest CR energies for Kolmogorov with toroidal
  MF.
• HS with high synchrotron cut-off (optical 1014
  Hz) are prone to be efficient astroparticle
  (secondaries from p-p and p-? interaction Ep
  (E?/1eV) gt 6.6 1016 eV) sources.
• Best candidate in Meisenheimer et al. 1989
  1997 list
• 3C273A (low radio power, high synchrotron
  cut-off, CR accelerator Ecrmax 7 x 1019 eV).
• Cygnus A (powerful radio source, low synchrotron
  cut-off 1012 Hz, not expected to be a strong
  astroparticle source.

21

• Astrophysics Jets Hot spots
• Hard spectra produced by multiple shocks
  acceleration (alternative radiative model)
• Oblique-perpendicular shocks with Kolmogorov
  type turbulence favored to produce high energy
  CRs
• Weaker radio but optical Hot spots are expected
  to be astroparticle sources
• - Good candidate 3C273A (transverse shock
  acceleration high synchrotron cut-off 1014
  Hz)