Development of a four-stage x-ray telescope for the DIOS (Diffuse Intergalactic Oxygen Surveyor) mission

摘要

Observation of diffuse soft X-rays with very low surface brightness can provide us cosmologically important information which is related to the missing baryon problem, large scale structure, etc. Diffuse Intergalactic Oxygen Surveyor(DIOS) mission is planned to observe such source, which may be originated by Warm Hot Intergalactic Medium(WHIM). For this purpose, the X-ray optical system designed under the condition of limited resource of the satellite, such as weight and size. Remarkable characteristic of this sysytem is to four time reflection to fit their observational instrument to the small satellite. Numerical simulations were performed to evaluate X-ray observational performance such as grasp, angular resolution, field of view. In addition to the promissing way of mirror fabrication, aluminum foil based epoxy replication method, it will also be described that the present status of four-stage full shell mirror development.