40—50MeV能区的银河γ射线源

GALACTIC GAMMA-RAY SOURCES IN 40—50MeV

长期以来在E100 MeV能区,银河系已知天体中只有船帆座脉冲星和蟹状星云脉冲星被SAS-2和COS-B卫星证认为γ射线源。我们分析COS-B数据得到了天鹅座X-3的γ射线像,使天鹅座X-3成为第三个被证认的银河高能γ点源,这是在这一能区中被证认的第一个γ射线双星。 COS-B卫星γ探测器可测能量下限为40 MeV,迄今所有已发表的分析COS-B数据的工作都只利用了50 MeV以上的事例。对于50 MeV以下光子COS-B探测器的性能比几百MeV时差得多:探测效率只有1%左右。

Image analysis has been made to the COS-B data in the measured energy range lower than 50 MeV. A gamin-ray flux map of the Galaxy in 40—50 MeV has been obtained. The three known γ sources at higher energies, the vela pulsar, Crab pulsar and Cyg X-3, are visible on the map. There are other strong point-like sources indicated by this analysis, their estimated positions and fluxes are given for four possible sources with intensities near to or stronger than that of the Crab.