White dwarf pulsars as possible electron-positron factories

We suggest that white dwarf pulsars can compete with neutron star pulsars for producing the excesses of cosmic ray positrons and electrons (e ^± ) observed by the PAMELA, ATIC/PPB-BETS, Fermi and H.E.S.S. experiments. A double degen- erate white dwarf binary mergers into a white dwarf pulsar with rotational energy (∼ 10⁵⁰erg) comparable to a neutron star pulsar. The birth rate (∼ 1=100yr) is also similar, providing the right energy budget. Applying the neutron star theory, we show that the white dwarf pulsars can produce e ^± , up to ∼ 10TeV for high magnetic fields (> 10⁸G). In contrast to the neutron star case, the adiabatic energy losses of e ^± are negligible since their injection continues after the nebula expansion. The long activity also enhances the nearby sources, potentially dominating the quickly cooled e ^± above TeV energy, detectable by the future AMS-02, CALET and CTA experiment.