High-energy emissions from the gamma-ray binary LS 5039

Abstract

We study mechanisms of multi-wavelength emissions (X-ray, GeV and TeV gamma-rays) from the gamma-ray binary LS~5039. This paper is composed of two parts. In the first part, we report on results of observational analysis using four year data of \fermi\ Large Area Telescope. Due to the improvement of instrumental response function and increase of the statistics, the observational uncertainties of the spectrum in $\sim$100-300 MeV bands and $>10$GeV bands are significantly improved. The present data analysis suggests that the 0.1-100GeV emissions from LS~5039 contain three different components; (i) the first component contributes to $<$1GeV emissions around superior conjunction, (ii) the second component dominates in 1-10GeV energy bands and (iii) the third component is compatible to lower energy tail of the TeV emissions. In the second part, we develop an emission model to explain the properties of the phase-resolved emissions in multi-wavelength observations. Assuming that LS~5039 includes a pulsar, we argue that both emissions from magnetospheric outer gap and inverse-Compton scattering process of cold-relativistic pulsar wind contribute to the observed GeV emissions. We assume that the pulsar is wrapped by two kinds of termination shock; Shock-I due to the interaction between the pulsar wind and the stellar wind and Shock-II due to the effect of the orbital motion. We propose that the X-rays are produced by the synchrotron radiation at Shock-I region and the TeV gamma-rays are produced by the inverse-Compton scattering process at Shock-II region.

51 pages, 15 figures, accepted for publication in ApJ

References in corpus (8)

• Precise Gamma-Ray Timing and Radio Observations of 17 Fermi Gamma-Ray Pulsars
• Discovery of High-Energy Gamma-Ray Emission from the Binary System PSR B1259-63/LS 2883 Around Periastron with Fermi
• HESS J0632+057 : A new gamma-ray binary?
• Periodic Emission from the Gamma-ray Binary 1FGL J1018.6-5856
• Unraveling the high-energy emission components of gamma-ray binaries
• Pulsar wind zone processes in LS 5039
• Pulsar model of the high energy phenomenology of LS 5039
• Probing the Pulsar Wind in the gamma-ray Binary System PSR B1259-63/SS 2883

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• Investigation of the energy dependence of the orbital light curve in LS 5039
• A dynamical and radiation semi-analytical model of pulsar-star colliding winds along the orbit: Application to LS 5039
• Radio absorption in high-mass gamma-ray binaries
• Broad-Band High-Energy Emission of the Gamma-ray Binary System LS 5039: Spectral and Temporal Features using NuSTAR and Fermi Observations
• Gamma-ray binaries beyond one-zone models: an application to LS 5039
• Swift monitoring of the massive X-ray binary SAX J0635.2+0533
• VERITAS Detection of LS 5039 and HESS J1825-137
• Unveiling properties of the non-thermal X-ray production in the gamma-ray binary LS 5039 using the long-term pattern of its fast X-ray variability