1FGL J1018.6–5856 is a high mass gamma-ray binary containing a compact object orbiting around a massive star with a period of 16.544 d.If the compact object is a pulsar,non-thermal emissions are likely produced by el...1FGL J1018.6–5856 is a high mass gamma-ray binary containing a compact object orbiting around a massive star with a period of 16.544 d.If the compact object is a pulsar,non-thermal emissions are likely produced by electrons accelerated at the termination shock,and may also originate from the magnetosphere and the un-shocked wind of the pulsar.In this paper,we investigate the non-thermal emissions from the wind and the shock with different viewing geometries and study the multi-wavelength emissions from 1FGL J1018.6–5856.We present the analysis results of the Fermi/LAT using nearly 10 years of data.The phase-resolved spectra indicate that the Ge V emissions comprise a rather steady component that does not vary with orbital motion and a modulated component that shows flux maximum around inferior conjunction.The ke V/Te V light curves of 1FGL J1018.6–5856 also exhibit a sharp peak around inferior conjunction,which are attributed to the boosted emission from the shock,while the broad sinusoidal modulations could be originating from the deflected shock tail at a larger distance.The modulations of Ge V flux are likely caused by the boosted synchrotron emission from the shock and the IC emission from the unshocked pulsar wind,while the steady component comes from the outer gap of the pulsar magnetosphere.Finally,we discuss the similarities and differences of 1FGL J1018.6–5856 with other binaries,like LS 5039.展开更多
基金supported by the National Key R&D Program of China (Grant No.2020YFC2201400)the National Natural Science Foundation of China (Grant No.U1838102)+1 种基金supported by the National Natural Science Foundation of China (Grant Nos.11822302 and 11833003)funded by the China Postdoctoral Science Foundation (Grant No.2020M682392)。
文摘1FGL J1018.6–5856 is a high mass gamma-ray binary containing a compact object orbiting around a massive star with a period of 16.544 d.If the compact object is a pulsar,non-thermal emissions are likely produced by electrons accelerated at the termination shock,and may also originate from the magnetosphere and the un-shocked wind of the pulsar.In this paper,we investigate the non-thermal emissions from the wind and the shock with different viewing geometries and study the multi-wavelength emissions from 1FGL J1018.6–5856.We present the analysis results of the Fermi/LAT using nearly 10 years of data.The phase-resolved spectra indicate that the Ge V emissions comprise a rather steady component that does not vary with orbital motion and a modulated component that shows flux maximum around inferior conjunction.The ke V/Te V light curves of 1FGL J1018.6–5856 also exhibit a sharp peak around inferior conjunction,which are attributed to the boosted emission from the shock,while the broad sinusoidal modulations could be originating from the deflected shock tail at a larger distance.The modulations of Ge V flux are likely caused by the boosted synchrotron emission from the shock and the IC emission from the unshocked pulsar wind,while the steady component comes from the outer gap of the pulsar magnetosphere.Finally,we discuss the similarities and differences of 1FGL J1018.6–5856 with other binaries,like LS 5039.
