2019ApJ...884..124F

The slow diffusion of cosmic rays could be common around pulsars as indicated by the recent observations of HAWC, which can significantly change the pulsar interpretation of the well-known positron excess. Meanwhile, the latest measurement by AMS-02 shows a clear high-energy cutoff in the positron spectrum. Here, we check all the identified pulsars under the two-zone diffusion model to explain the new AMS-02 data. We find that the candidates must be nearby and middle-aged. Geminga, which was generally believed to be a very likely candidate, has recently been disfavored by Fermi-LAT observations of the GeV γ-ray flux. Following recent studies which indicate that PSR B1055-52 is much closer to the Earth than previously assumed, we propose for the first time that PSR B1055-52 is the most promising source of the positron excess. PSR B1055-52 can well reproduce both the intensity and the high-energy cutoff of the AMS-02 positron spectrum.