Clusters of galaxies are the largest bound systems in the Universe. They
are located at the knots of the cosmic web and therefore are important
tracers of the large-scale structure of the Universe. They provide
various environments for galaxies and affect their evolution. They are
formed by merging process, hence have diverse states of dynamics shown
in optical and X-ray images.
In early days, galaxy clusters were identified from optical surveys,
as the most famous cluster catalog obtained by
Abell
and his successors. Recently, data of many large sky area
surveys are available, such
as
the Sloan Digital Sky Survey (SDSS),
SuperCOSMOS,
the Wide-field Infrared Survey Explorer (WISE)
and unWise,
the Hyper Suprime-Cam Subaru strategic program (HSC-SSP),
the Dark Energy Survey (DES) and
the DESI Legacy Imaging Surveys. From these survey data,
we have identified a great number of clusters of galaxies: See here:
Many catalogs of clusters of galaxies we obtained!
Based on these large samples of clusters and public data, we studied the properties of clusters, including dynamical states of clusters, radio emission from clusters, the constraints of cosmological parameters, and discovery of giant lensed arcs by clusters. See many details here!
Recently a new method to determine the dynamical states of clusters of galaxies has been developed. We got dynamical state evaluated for 964 X-ray clusters observed by the Chandra observatory and 1308 X-ray clusters observed by the XMM-Newton observatory. They are combined for form a sample of 1844 clusters with all dynamical states evaluated.
Publications: