@Italian] and to produce a steep enough spectrum [@HooperWeiner]. Gamma rays and radio measurements also generate significant constraints [@Cirelli; @Bergstrom], since the charged SM byproducts of the annihilation may emit either hard final state radiation or synchrotron emission in the galactic magnetic field. In short, if the positron excesses are to be explained in terms of annihilating Weakly Interacting Massive Particle, the WIMP must have non-standard properties. There are possible exceptions to these conclusions in the case that we happen to be nearby a dense clump of dark matter [@clump], or for non-standard propagation models [@Michigan].

The cosmic ray positron excess may be purely astrophysical, however. There are several possible astrophysical explanations. The excess may result from secondary production and acceleration in the cosmic ray source itself [@BlasiCR]. Supernova remnants may also produce highly energetic positrons to explain the PAMELA signal [@Piran]. It has been noted many times that a single or few pulsars in the neighborhood of a kiloparsec from us, or a distribution of pulsars, may contribute $e^+e^-$ with an energy spectrum that can reproduce the steep rise over the $E^{-3}$ background seen in PAMELA [@Atoian:1995ux; @Chi:1995id; @ChengZhang; @Blasi; @Yuksel:2008rf; @Profumo; @Malyshev:2009tw].

In this paper we explore the 