Astroseminar Series - Hanyu Zhang - HYBRID

Wednesday, September 20, 2023 11:30 am - 11:30 am EDT (GMT -04:00)

Hanyu Zhang
Hanyu Zhang is a postdoctoral fellow at the Waterloo Centre for Astrophysics. He completed his Ph.D in physics at Kansas State University under the supervision of Dr. Lado Samushia. Hanyu is actively involved in the DESI collaboration, contributing to various projects, working groups, and co-leading the Galaxy-Halo Connection topical group.

Title: Towards better understanding of galaxy-halo connection using DESI

Abstract: The Dark Energy Spectroscopic Instrument (DESI) survey presents a unique opportunity to investigate the nature of dark energy and the evolution of the universe, offering an abundance of data that can enhance our comprehension of both the galaxy-halo connection and cosmological parameters. In this talk, I will present the Halo Occupation Distribution (HOD) analysis of Luminous Red Galaxy (LRG), Quasi-Stellar Object (QSO) samples and Emission Line Galaxies (ELGs) derived from the One-Percent survey conducted by DESI. We scrutinize the HOD parameters as well as physical parameters such as the satellite fraction and mean halo mass of LRGs within a redshift range of 0.4<z<1.1 and detect clear trends of redshift evolution for these physical parameters. Additionally, we emphasize the significance of higher-order statistics, such as the projected three-point correlation function, for constraining the galaxy-halo connection. While two-point statistics have been extensively utilized, we demonstrate that the additional information provided by higher-order statistics enables us to glean more information on 1-halo scales and constrain the HOD parameters with greater precision. We adopt and generalize a swift HOD fitting pipeline to significantly reduce the required computation time for the three-point analysis.