We investigate, in terms of production from pulsars and their nebulae, the cosmic ray positron and electron fluxes above ~10 GeV, observed by the AMS-02 experiment up to 1 TeV. We concentrate on the Vela-X case. Starting from the gamma-ray photon spectrum of the source, generated via synchrotron and inverse Compton processes, we estimated the electron and positron injection spectra. Several features are fixed from observations of Vela-X and unknown parameters are borrowed from the Crab nebula. The particle spectra produced in the pulsar wind nebula are then propagated up to the Solar System, using a diffusion model. Differently from previous works, the omnidirectional intensity excess for electrons and positrons is obtained as a difference between the AMS-02 data and the corresponding local interstellar spectrum. An equal amount of electron and positron excess is observed and we interpreted this excess (above ~100 GeV in the AMS-02 data) as a supply coming from Vela-X. The particle contribution is consistent with models predicting the gamma-ray emission at the source. The input of a few more young pulsars is also allowed, while below ~100 GeV more aged pulsars could be the main contributors.

Della Torre, S., Gervasi, M., Rancoita, P., Rozza, D., Treves, A. (2015). Pulsar Wind Nebulae as a source of the observed electron and positron excess at high energy: The case of Vela-X. JOURNAL OF HIGH ENERGY ASTROPHYSICS, 8, 27-34 [10.1016/j.jheap.2015.08.001].

Pulsar Wind Nebulae as a source of the observed electron and positron excess at high energy: The case of Vela-X

GERVASI, MASSIMO;ROZZA, DAVIDE;
2015

Abstract

We investigate, in terms of production from pulsars and their nebulae, the cosmic ray positron and electron fluxes above ~10 GeV, observed by the AMS-02 experiment up to 1 TeV. We concentrate on the Vela-X case. Starting from the gamma-ray photon spectrum of the source, generated via synchrotron and inverse Compton processes, we estimated the electron and positron injection spectra. Several features are fixed from observations of Vela-X and unknown parameters are borrowed from the Crab nebula. The particle spectra produced in the pulsar wind nebula are then propagated up to the Solar System, using a diffusion model. Differently from previous works, the omnidirectional intensity excess for electrons and positrons is obtained as a difference between the AMS-02 data and the corresponding local interstellar spectrum. An equal amount of electron and positron excess is observed and we interpreted this excess (above ~100 GeV in the AMS-02 data) as a supply coming from Vela-X. The particle contribution is consistent with models predicting the gamma-ray emission at the source. The input of a few more young pulsars is also allowed, while below ~100 GeV more aged pulsars could be the main contributors.
Articolo in rivista - Articolo scientifico
Astroparticle physics; Cosmic rays; Local interstellar spectrum; Pulsar wind nebulae; Pulsars;
English
27
34
8
Della Torre, S., Gervasi, M., Rancoita, P., Rozza, D., Treves, A. (2015). Pulsar Wind Nebulae as a source of the observed electron and positron excess at high energy: The case of Vela-X. JOURNAL OF HIGH ENERGY ASTROPHYSICS, 8, 27-34 [10.1016/j.jheap.2015.08.001].
Della Torre, S; Gervasi, M; Rancoita, P; Rozza, D; Treves, A
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/88230
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