High-energy Research On Colliding-wind-binary Based On FERMI-LAT Data

Colliding wind binaries typically are binaries or multiple systems formed with massive early-type stars and Wolf-Rayet starsfWR stars).It exits a winds colliding region(WCR)produced by stellar winds colliding between the two stars.The shocks in the region can accelerate particles to relativistic velocity.Then the particles can be cooled through synchrotron radiation or Inverse Compton ra.diation and emit non-thermal radio,X-rays and γ rays.The relativistic par-ticles accelerated in the shock are very important for us to study acceleration mechanisi,the origin of cosmic rays and high energy radiation.In the paper,we firstly introduce the knowledge of colliding wind binaries,including structure,evolution,observations and theoretical analysis of radio、X-ray and γ-ray radiation.We also emphasize on the only CWB,"η Carinae“,which is γ-ray source.CWBs have been considered as a possible high-energy γ-ray sources for long time,however no system other than η Carinae has been detected.To find the other gamma ray radiation from colliding wind binaries,we use the nine-year-data from Fermi-LAT to process and analysis 18 particle acceleration colliding wind binaries.We find that the significant γ-ray signal in the spatial position of CEN 1 that we focus on,in the range of 1GeV-500GeV,the intergral photon flux is about(1.49 ± 0.32)×10-9 photon cm-2s-1 with the confidence level of 6.7σ with statistical error.There is a break at 10-20GeV in the energy spectrum.The photon spectrum can be well described by a power law with an index ofΓ=2.36±0.16.Above 20GeV,a hard gamma-ray tail is similar to another gamma-ray source η Carinae.As a result,the high energy radiation from CEN1 is mostly like from the radiation from π0 decay.Possibly CEN 1 is another γ ray source.Besides,through the data from Fermi-LAT that we handled,we find no gamma-rays in the other 17 colliding wind binaries.We calculate the gamma ray flux upper limit of the 17 sources.For system-9 Sgr,we calculate the gamma ray radiation through leptonic model:Inverse Compton scattering、relativistic bremsstrahlung and hadronic model:π0 decay.Compared to flux upper limit from observation we cannot exclude any radiation mechanisms.Chapter four is the summary and forecasting.The high energy radiation of CEN 1 need more precise measurements from HESS or CTA to search TeV or PeV radiation.Further more,to find more gamma ray sources,more other colliding wind binaries candidates could be selected and searched.