Cosmic ray electrons and positrons represent only _ 1% of the total particles which reach the Earth. The standard scenario predicts that the main component of the electron spectrum is the one produced by supernova remnants, while positrons are supposed to be mainly originated from the decay of muons produced by cosmic ray interactions with the interstellar medium. In the last years, space born experiments, like AMS-02, have detected an anomalous electron and positron abundance with respect to the theoretical model predictions, for energy above _ 10 GeV, where the solar modulation e_ects are negligible. This di_erence, between data and model prediction, shows an extra contribution suggesting an equal amount for both electrons and positrons. These kinds of particles, with an initial energy of 100 GeV, can travel at most for _ 2 kpc; thus, a source of electron-positron pairs is expected inside this region. We studied the contribution from Vela-X Pulsar Wind Nebula starting from its photon spectrum; a di_usion model is applied from the source up to the Solar System and the propagated spectra are compared with the AMS-02 data. Above 100 GeV, Vela-X is the main candidate to contribute to the observed excess and it could give an anisotropic signal in the arrival cosmic ray directions.

Astrophysical sources for the observed electron and positron axcess at high energy with AMS-02 experiment / Rozza, Davide. - (2015).

Astrophysical sources for the observed electron and positron axcess at high energy with AMS-02 experiment.

Rozza, Davide
2015-01-01

Abstract

Cosmic ray electrons and positrons represent only _ 1% of the total particles which reach the Earth. The standard scenario predicts that the main component of the electron spectrum is the one produced by supernova remnants, while positrons are supposed to be mainly originated from the decay of muons produced by cosmic ray interactions with the interstellar medium. In the last years, space born experiments, like AMS-02, have detected an anomalous electron and positron abundance with respect to the theoretical model predictions, for energy above _ 10 GeV, where the solar modulation e_ects are negligible. This di_erence, between data and model prediction, shows an extra contribution suggesting an equal amount for both electrons and positrons. These kinds of particles, with an initial energy of 100 GeV, can travel at most for _ 2 kpc; thus, a source of electron-positron pairs is expected inside this region. We studied the contribution from Vela-X Pulsar Wind Nebula starting from its photon spectrum; a di_usion model is applied from the source up to the Solar System and the propagated spectra are compared with the AMS-02 data. Above 100 GeV, Vela-X is the main candidate to contribute to the observed excess and it could give an anisotropic signal in the arrival cosmic ray directions.
2015
Cosmic ray, AMS-02, pulsar wind, nebula, astropartycle physics
Astrophysical sources for the observed electron and positron axcess at high energy with AMS-02 experiment / Rozza, Davide. - (2015).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11383/2090798
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