The Fermi LAT Collaboration, M. J. Coe, F. Di Mille, P. G. Edwards, M. D. Filipović, J. L. Payne, J. Stevens, M. A. P. Torres
Gamma-ray binaries are stellar systems containing a neutron star or black
hole with gamma-ray emission produced by an interaction between the components.
These systems are rare, even though binary evolution models predict dozens in
our Galaxy. A search for gamma-ray binaries with the Fermi Large Area Telescope
(LAT) shows that 1FGL J1018.6-5856 exhibits intensity and spectral modulation
with a 16.6 day period. We identified a variable X-ray counterpart, which shows
a sharp maximum coinciding with maximum gamma-ray emission, as well as an
O6V((f)) star optical counterpart and a radio counterpart that is also
apparently modulated on the orbital period. 1FGL J1018.6-5856 is thus a
gamma-ray binary, and its detection suggests the presence of other fainter
binaries in the Galaxy.
View original:
http://arxiv.org/abs/1202.3164
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