Pasquale Blasi
(INAF)
05/08/2015, 14:00
CR-TH
Oral contribution
Ultra-high energy cosmic rays observed at the Earth are most likely accelerated in extra-galactic sources. For typical source luminosities invoked for such sources, we show that the electric current associated with cosmic rays escaping their sources is large enough to induce plasma instabilities that create magnetic fluctuations able to confine particles close to their sources for energies...
denise boncioli
(INFN - LNGS)
05/08/2015, 14:15
CR-TH
Oral contribution
In the last years a general consensus has emerged that ultra-high energy
cosmic ray (UHECR) data can serve as a powerful probe of the validity of
special relativity. This applies in particular to the propagation of cosmic
rays from their sources to Earth through diffuse extragalactic background radiation, which is responsible for energy
suppressions due to pion photoproduction by UHE...
Iris Gebauer
05/08/2015, 14:30
CR-TH
Oral contribution
The positron fluxes measured by PAMELA and most recently
AMS-02, show an excess far above the expectations of secondary positron
production in the ISM. These locally observed energetic positrons
require a near-by source of even more energetic positrons.
Among the possible explanations for a primary source of such positrons,
unaccounted astrophysical point sources or dark
matter (DM)...
Elena Orlando
(Stanford University)
05/08/2015, 14:45
CR-TH
Oral contribution
Cosmic rays (CR) interact with the interstellar medium and the magnetic field in the Milky Way, producing diffuse emission from radio to gamma rays. Observations of this diffuse emission and comparison with detailed predictions are powerful tools to unveil the CR distribution and to study CR propagation. We present various GALPROP CR propagation scenarios based on current CR measurements. The...
Christo Venter
(North-West University, Potchefstroom Campus)
05/08/2015, 15:00
CR-TH
Oral contribution
Pair cascades from MSPs may be a primary source of Galactic electrons and positrons that contribute to the increase in positron flux above 10 GeV as observed by PAMELA and AMS-02. The Fermi Large Area Telescope has increased the number of detected gamma-ray millisecond pulsars (MSPs) tremendously. Light curve modelling furthermore favours abundant pair production in MSP magnetospheres, so that...
Dr
Giovanni Morlino
(Gran Sasso Science Institute)
05/08/2015, 15:15
CR-TH
Oral contribution
Cosmic rays (CR) are a fundamental source of ionization for molecular clouds as well as diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of CR inside a cloud also determines the γ-ray flux produced by hadronic collisions between CR and cloud materials. We study the spectrum of CR inside and outside a diffuse cloud for energies > MeV. We solve the...
Julian Krause
05/08/2015, 15:30
CR-TH
Oral contribution
Molecular clouds act as targets for cosmic ray interactions, such as gamma ray emission via proton proton interactions. We study the effect of ionization by cosmic ray electrons and protons. Complimentary to gamma ray emission, the ionization rate allows to estimate the cr flux. In particular the ionization rate allows access to proton energies below the pion production threshold (~ 270 MeV)....
Martina Cardillo
(INAF - Osservatorio astrofisico di Arcetri)
05/08/2015, 15:45
CR-TH
Oral contribution
While from the energetic point of view supernova remnants are viable sources of Galactic cosmic rays (CRs), the issue of whether they can accelerate protons up to a few PeV remains unsolved. Here we discuss particle acceleration at the forward shock of supernovae, and discuss the possibility that the current of escaping particles may excite a non-resonant instability that in turn leads to the...
