The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray Space Telescope data between 2008 August and 2009 June are presented. Our results indicate variability that is consistent with the binary period, with the emission being modulated with a period of 3.903 +/- 0.005 days; the first detection of this modulation at GeV energies. The light curve is characterized by a broad peak around superior conjunction in agreement with inverse Compton scattering models. The spectrum is represented by a power law with an exponential cutoff, yielding an overall flux ( 100 MeV-300 GeV) of 4.9 +/- 0.5(stat) +/- 1.8(syst) x 10(-7) photon cm(-2) s(-1), with a cutoff at 2.1 +/- 0.3(stat) +/- 1.1(syst) GeV and photon i...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
New observations of LS 5039, a High Mass X-ray Binary comprising a massive star and compact object, ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
New observations of LS 5039, a High Mass X-ray Binary comprising a massive star and compact object, ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
The first results from observations of the high-mass X-ray binary LS 5039 using the Fermi Gamma-ray ...
New observations of LS 5039, a High Mass X-ray Binary comprising a massive star and compact object, ...