Wide Sky Survey For Gamma Ray Point Sources With ARGO-YBJ Experiment

Cosmic rays are high-energy particles coming from the astrospace,analyzing the cosmic rays is one of the most important ways to get the information of the celestial bathes.The origin,acceleration and propagation of cosmic ray are fundamental yet unresolved problems of cosmic ray(CR)physics.In the dissemination process,as a neutral particle,gamma ray can keep the information of cosmic ray source as it's not deflected by magnetic field on its way to observer and therefore is regarded as the best probe in understanding those problems.Through observe theγpoint sources,also help us to better understanding of the basic question of the cosmic rays origin,accelerate and propagation.YangBaJing International Cosmic Ray Observatory Located in Tibet,at an altitude of 4300m above sea level,hosts two Extensive Air Shower cosmic ray experiments(ARGO and AS_γ).The high altitute advantages allow for the study of a wide range of fundamental in cosmic ray and astroparticle physics,with its unique physical geography advantage,at similar experimental device has a minimum threshold and the highest count rate shower can be observed,one of the main physical goal of the ARGO-YBJ experiment is to detect from inside and outside the Galaxyγpoint source on the space.The observation on high energy gamma ray mainly includes experiment based on satellite experiment,Air Cherenkov Telescope(ACT)experiments and Extensive Air Shower(EAS) array etc.Satellite experiments have an advantages of direct measurement and high resolution,but the weakness is the cost too expensive;Air Cherenkov Telescope experiments has a very good resolution with hadron and photon,however,the gas and the environment makes the observation time is extremely limited.Extensive Air Shower(EAS) array with the capacity of large field of view and nearly 100%duty cycle,they are particularly suitable for the study of variableγray sources.In this paper,we use ARGO-YBJ experiment reconstruction datas from July 2006 to June 2007.A fast wide sky survey analysis based on the equi-zenth method was developed and applied for analysis.The field of all sky in the declination band between 10°-70°is searched for the very high-energy gamma ray sources with the all-sky survey method.The first chapterⅠof the thesis mainly reviews the cosmic ray background knowledge,γastronomy and gamma-ray source detection means,the source ofγ-ray point sources of research;chapterⅡintroduces the ARGO-YBJ experiment and reconstruction data samples; ChapterⅢintroduces this rapid all sky survey methods and Monte-Carlo simulation testing; ChapterⅣgiven the scanning search phase results ofγpoint sources,using the all-sky method analyzed One-year datas and given the center positions of significant that more than 4σ,Crab Nebula and Mrk421 significants in excess 6σ;also analysis each month datas given the distribution of two-dimensional maps around the sources that significant more than 4.5σ. The results showed eight positions which significantly greater than 3σand in close proximity with the Egret-Ⅲ.