BEXCO - Room F(201/202/203/204)
[GA319] Observations of the gamma-ray binary system LS 5039 with H.E.S.S. and Fermi-LAT
- Christian MARIAUD
- Christian MARIAUD (Laboratoire Leprince Ringuet Ecole Polytechnique, Palaiseau, France)
LS 5039 is a binary system located at 3.5 kpc from the Earth. It is composed of a compact object orbiting around a O6.5V star every ~3.9 days in a moderately eccentric orbit (e = 0.35) and emitting light across the whole electromagnetic spectrum, from radio to gamma-rays. The system displays a periodic spectral modulation related to the orbital motion of the compact object. The spectral variatons can now be characterized at an unprecedentedly high accuracy level in the energy range from 100 MeV to 10 TeV. In this contribution, we report here on a combined study of the properties of the source at high and very-high energies, making use of 7 years of Fermi-LAT observations covering the energy range 100 MeV to 500 GeV, and 12 years of H.E.S.S. data at energies above 100 GeV. The combined results from the two instruments provides us with an improved characterization of the source spectrum during superior and inferior conjunctions. It also allows us to study the physics behind the gamma-ray production in LS 5039, in every orbital phase bin.