Shota Kisaka, Norita Kawanaka
Recent {\gamma}-ray observations suggest that the {\gamma}-ray millisecond
pulsar (MSP) population is separated into two sub-classes with respect to the
pair multiplicity. Here, we calculate the cosmic ray electron/positron spectra
from MSPs. Based on the assumption of the equipartition in the pulsar wind
region the typical energy of electrons/positrons ejected by a MSP with the pair
multiplicity of order unity is \sim 50 TeV. In this case, we find that a large
peak at 10 - 50 TeV energy range would be observed in the cosmic ray
electron/positron spectrum. Even if the fraction of pair starved MSPs is 10%,
the large peak would be detectable in the future observations. We also
calculate the contribution from MSPs with high pair multiplicity to the
electron/positron spectrum. We suggest that if the multiplicity of dominant MSP
population is \sim 10^3, electrons/positrons from them may contribute to the
observed excess from the background electron/positron flux and positron
fraction.
View original:
http://arxiv.org/abs/1112.5312
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