SUPERNOVA EXPLOSIONS :
the best Candidate for the Source of the GALACTIC COSMIC RAYS:
[1.] Energy Balance Considerations
[2.] Spectrum Shape
Energia in RAGGI COSMICI
Condizione di Stazionarieta' T(Galaxy) years
T(cr) years
Potenza Necessaria per rinnovare la Popolazione di Raggi Cosmici
Potenza-In = Potenza-Out
Potenza-Out = Energia -Raggi Cosmici Tempo di Confinamento
= Energy density *Volume Tempo di
Confinamento
Energy Density of Cosmic Rays
Energy Balance
SuperNova possible ContributionMAXIMUM ENERGY
of the ACCELERATION
Two conditions :
The accelerated Particle must Remain confined in the Accelerator
The lifetime of the accelerator must be
sufficiently long to have time to accelerate
up to the highest energy.
Magnetic Confinement
Condition of the Acceleration Time
Need to compute the lifetime of the accelerator
The “Acceleration Rate”
Lifetime of a SuperNova Remnant:
The “sweeped mass” is of the same order of the ejected mass.
v1/v2~4
Bohm diffusion in magnetic field
E
vshocktacc=R
Estimate for SuperNovae
What is this Energy ? The “Knee” ?
What Sources can produce the Highest energy Cosmic Rays ?
Condition on :
Size * Magnetic Field
“HILLAS PLOT”
“HILLAS PLOT”
SNR p 100 EeV
RADIATION PROCESSES
from
COSMIC RAY SOURCES
e± p
Astrophysical Object containing:
Populations of
relativistic protons, Nuclei electrons/positrons
Emission of:
rays
Neutrinos Cosmic Rays
Cosmic Ray Sources
Emissions of High energy:
Photons Neutrinos
Power Law
Energy Spectrum of protons
Processes involving Protons
Photons
Neutrinos
Photon Emission
Number of photons
emitted per unit time and unit energy.
Intermediate Step: Production Rate of
the parent particles 0
Hadronic Cross section:
Two different Energies (100, 175 GeV)
Feynman Scaling
(Approximate Validity) Important consequence
Result:
If the primary Particle spectrum is a power Law of “slope” alpha:
The Inclusive hadronic Cross sections are Feynman scaling:
The secondary Particle spectrum is again a power law spectrum with the same slope:
The proportionality coefficient is a “Z-factor”
