Hierarchical clustering and the baryon distribution in galaxy clusters
نویسندگان
چکیده
The baryon fraction of galaxy clusters in numerical simulations is found to be dependant on the cluster formation method. In all cases, the gas is anti-biased compared with the dark matter. However, clusters formed hierarchically are found to be more depleted in baryons than clusters formed non-hierarchically. There is a depletion of 10 to 15% for hierarchically formed clusters while the depletion is less than 10% for those clusters formed non-hierarchically. This difference is dependent on the mass of the clusters. The mean baryon enrichment profile for the hierarchically formed clusters shows an appreciable baryon enhancement around the virial radius not seen in the clusters formed without substructure. If this phenomenon applies to real clusters, it implies that determinations of the baryon fractions in clusters of galaxies require data extending beyond the virial radius of the clusters in order to achieve an unbiased value.
منابع مشابه
اندازهگیری نمایه عمق نوری خوشههای کهکشانی با استفاده از اثرسونیائف زلدوویچ جنبشی
baryonic matter distribution in the large-scale structures is one of the main questions in cosmology. This distribution can provide valuable information regarding the processes of galaxy formation and evolution. On the other hand, the missing baryon problem is still under debate. One of the most important cosmological structures for studying the rate and the distribution of the baryons is gal...
متن کاملGraph Clustering by Hierarchical Singular Value Decomposition with Selectable Range for Number of Clusters Members
Graphs have so many applications in real world problems. When we deal with huge volume of data, analyzing data is difficult or sometimes impossible. In big data problems, clustering data is a useful tool for data analysis. Singular value decomposition(SVD) is one of the best algorithms for clustering graph but we do not have any choice to select the number of clusters and the number of members ...
متن کاملChoosing the Best Hierarchical Clustering Technique Based on Principal Components Analysis for Suspended Sediment Load Estimation
1- INTRODUCTION The assessment of watershed sediment load is necessary for controling soil erosion and reducing the potential of sediment production. Different estimates of sediment amounts along with the lack of long-term measurements limits the accessibility to reliable data series of erosion rate and sediment yield. Therefore, the observed data of suspended sediment load could be used to ...
متن کاملLuminous Matter Distribution, Bulk Flows and Baryon Contents in Cosmological Models with a Local Void
First galaxy formation is discussed from the viewpoint of hierarchical clustering theory and it is shown that inhomogeneous models with a local void may be compatible with the observed homogeneity of galactic distributions given by recent redshift surveys, because of the difference in the feedback system of galaxy formation in the inner and outer regions. Next it is shown that the observed inho...
متن کاملLuminous Matter Distribution, Bulk Flows and Baryon Content in Cosmological Models with a Local Void
First, we consider galaxy formation from the viewpoint of hierarchical clustering theory and discuss the possibility that inhomogeneous models with a local void may be compatible with the observed homogeneity of galactic distributions found in recent redshift surveys, because their inhomogeneity can be weakened by the difference in the feedback system of galaxy formation between the inner and o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1999