The Calorimetric Electron Telescope (CALET) is scheduled to be launched to the ISS before October of this year and will measure the energy and direction distribution of electron+positron cosmic rays well into the TeV range during a 5-year mission. With a 1: 105 proton rejection rate and an energy resolution of 2%, it is capable of detecting even small features in the spectrum. Combining the measurement of the total electron and positron flux by CALET with the positron fraction data from the AMS-02 experiment, it will be possible to significantly constrain models of Dark Matter annihilating in the galactic halo. Assuming the positron excess is caused by an astrophysical single power law source emitting an equal amount of electrons and positrons, the expected Dark Matter limits for 5-yr are presented, based on simulated data for CALET together with the recent positron fraction of AMS-02. These predictions are compared to limits derived with the same procedure using current experimental data. While this power law source explaining the positron excess could be a single nearby pulsar, the large number of pulsars discovered by radio and X-ray telescopes makes an overlapping spectrum from several strongly contributing sources likely. Based on a numerical cosmic ray propagation simulation, the cosmic-ray spectra from nearby pulsar wind nebulae have been calculated and the expected capability of CALET to discern the multiple overlapping spectra, with parameters chosen to explain the observed cosmic ray excess, from the single power law spectrum of one pulsar is shown.
|出版ステータス||Published - 2015|
ASJC Scopus subject areas