July 29, 2015 to August 6, 2015
World Forum
Europe/Amsterdam timezone

Cosmic-ray positron measurements: on the origin of the e+ excess and limits on magnetar birthrate

Jul 30, 2015, 3:30 PM
Amazon Foyer (World Forum)

Amazon Foyer

World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Board: 199
Poster contribution CR-TH Poster 1 CR


Catia Grimani (University of Urbino "Carlo Bo")


Positrons were discovered in cosmic rays 50 years ago. During the last 25 years, reliable magnetic spectrometer observations consistently revealed an excess of these particles above a few GeV with respect to the expected secondary component. The most recent measurements of the positron flux and the e+/(e++e-) ratio carried out by the Pamela and AMS experiments confirm the average trend of previous magnetic spectrometer observations up to 50 GeV and indicate that this excess is observed up to about 500 GeV. Many different hypotheses were suggested in the literature to explain these observations. However, when the characteristics of possible sources of e+ are taken into account, astrophysical objects and in particular, pulsars and, possibly, magnetars, remain the most plausible candidates even if disk formation may critically affect the actual contribution of these stars to cosmic-ray positrons. The magnetar birthrate is revised within the proposed scenario.
Collaboration -- not specified --
Registration number following "ICRC2015-I/" 0001

Primary author

Catia Grimani (University of Urbino "Carlo Bo")

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