Abstract:
According to star formation history, it is important to study the properties of the galaxies and their environmental dependence at z=1~2. But there are not so many statical studies of high-z clusters because high-z galaxy clusters are rare and member galaxies are very faint. Then we used HSC-SSP data which have larger field of view and deeper than previous surveys and we tried to contruct a large sample of galaxy clusters at z = 0.5~1.2. We carried out two surveys. At first, we conducted “Blue cloud survey”, in which we found over-density regions of star-formation galaxies by using narrow band filter to catch [OⅡ] or [OⅢ] emission. Secondary, we conducted ""Red sequence survey”, in which we found over-density regions of red sequence galaxies by using broad band filter for color selection. We named these two survey as ""HSC-HSC , which stand for Hybrid Search for Cluster with HSC. We could find a lot of galaxy cluster candidates (Blue cloud survey; 86, Red sequence survey; 199 ). Especially in ""Blue cloud survey"", the candidates dominated by emission line galaxies were found. We studied properties of these cluster candidates by using color-magnitude diagram, luminosity function and so on. We could confirm ""down sizing"". Our results suggest that they may be younger stage of galaxies clusters.