Possible Streams Of The Galactic Globular Clusters And Halo Stars

Stellar streams is defined as the assembly of the relic stars and interstellar matterof the globular clusters and/or nearby dwarf galaxies which are torn into pieces by thetidal force of the major galaxy. Such phenomenon is a prediction from the cold darkmatter model of cosmology, also a hot topic in recent years. This thesis introducesthe origin and current research of stellar streams in details, defines clearly a stellarstream, gives the observational evidence of stellar streams, summarizes the methods todiscover and the list of known stellar streams. By analyzing the kinematical propertiesof the objects, we search of the streams of Galactic globular clusters and the halo stars.This method based on the assumption that the members of a given stream share thesame specific angular momentum and energy and locate in the same orbit. Makinguse of the database of 150 globular clusters by Harris, 5 possible streams of globularclusters in our Galaxy are suggested. In one of these streams, three globular clustersare the member of the widely accepted Sagittarius stream. From the SDSS (SloanDigitized Sky Survey) DR6, the BHB (Blue Horizontal Branch) stars are picked outmainly according to the spectral type classification. From more than 2000 BHB stars,four possible streams are traced, while further analysis of the properties such as radialvelocity and metallicity is in plan. For all these possible streams, the orbital parametersare derived. The errors are analyzed as well.