2024年11月14日，周四15:30-17:00

紫金港西区海纳苑8幢324

New Frontiers of Dark Matter Halo (暗物质晕的新前沿）

韩家信（上海交通大学）

Abstract：

Current theoretical understandings of the nonlinear structure formation and galaxy formation processes are largely built upon a central concept that dark matter in the Universe are mostly contained in virialized clumps called dark matter halos, with the boundary of a halo described by its virial radius. However, the growth of a halo means it is inevitably surrounded by a non-virialized envelope of freshly accreted material. Failing to account for this envelope has led to major difficulties in the classical halo model, while a number of recent works have attempted to solve the problems by redefining the halo with new boundaries.

In this talk I will report our recent development of the depletion radius, which is a new but fundamental halo boundary stemming from the macroscopic physics of halo growth. I will show that the depletion radius is both an important physical probe of halo evolution and a concise geometric boundary for halo models of the large scale structure, capable of overcoming major limitations of the classical halo in a systematic way. I will also present our observational measurements of the depletion radius for both our Milky Way halo and DESI galaxy groups.

欢迎老师和同学们参加！