  The evidence of a line-like spectral feature at 130 GeV recently reported
from some parts of the galactic plane poses serious challenges for any
interpretation of this surprise discovery. It is generally believed that the
unusually narrow profile of the spectral line cannot be explained by
conventional processes in astrophysical objects, and, if real, is likely to be
associated with Dark Matter. In this paper we argue that cold ultrarelativistic
pulsar winds can be alternative sources of very narrow gamma-ray lines. We
demonstrate that Comptonization of a cold ultrarelativistic electron-positron
pulsar wind in the deep Klein-Nishina regime can readily provide very narrow
distinct gamma-ray line features. To verify this prediction, we produced photon
count maps based on the Fermi LAT data in the energy interval 100 to 140 GeV.
We confirm earlier reports of the presence of marginal gamma-ray line-like
signals from three regions of the galactic plane. Although the maps show some
structure inside these regions, unfortunately the limited photon statistics do
not allow any firm conclusion in this regard. The confirmation of 130 GeV line
emission by low-energy threshold atmospheric Cherenkov telescope systems, in
particular by the new 27 m diameter dish of the H.E.S.S. array, would be
crucial for resolving the spatial structure of the reported hotspots, and thus
for distinguishing between the Dark Matter and Pulsar origins of the `Fermi
Lines'.
