Fermi-LAT detection of proton acceleration signature in Supernova Remnant
by
Carmelo Sgro'(PI)
→
Europe/Rome
250 (INFN)
250
INFN
Description
Supernova Remnants (SNR) have long been suspected of accelerating cosmic rays.
However, unequivocal evidence for the acceleration of protons, which is the major component of cosmic rays, is still lacking.
An important piece of the puzzle has been recently added by the Fermi-LAT that measured the gamma-ray spectra of two bright SNRs starting from 60 MeV and detected a signature of proton acceleration.
In fact, if protons are accelerated in these sources, they can interact with the ambient gas and produce neutral pions, which in-turn decay into gamma rays.
One clear signature of this scenario is the existence of a low-energy cutoff (pion-bump) in the gamma-ray spectra at ~67MeV.
In this talk we will discuss the Fermi-LAT result, the measurement of the spectra and the identification of the signature.
We will also discuss the implication for cosmic-ray proton acceleration.
