Lunch talk on Sep. 28, 2026

Identification and research of X-ray extended galaxy clusters and dark matter halos

Speaker: Weiwei Xui (NAOC)

Venue: SWIFAR Building 2111

Time: 12:45 PM, Monday, Sep. 28, 2026

Abstract: 

To explain the well-known tension between cosmological parameter constraints obtained from the primary cosmic microwave background (CMB) and those drawn from X-ray-selected galaxy cluster samples identified with early data, we propose a possible explanation for the incompleteness of detected clusters being higher than estimated, and suggest that certain types of galaxy groups or clusters may have been overlooked in previous works. In this talk, I will present our projects to identify and research galaxy clusters with especially extended X-ray surface brightness distributions, using a dedicated algorithm optimized for extended sources. I will also show some preliminary results with the EP-FXT data. In addition, I will show our series of work to constraint the average halo profiles with the galaxy-galaxy lensing (gglens) method, such as the concentration-mass relation, the splashback radius of halos, and the prediction of gglens performance with CSST data.