Shanghai Astronomical Observatory Astrophysics Colloquium

Title：Deconstruction of galaxies: bulges, disks, and halos

Speaker：Prof. Min Du (Xiamen University)

Location: Lecture Hall, 3rd floor

Tencent Conference ID: 429-1540-0486 password: 6360

Time：3:00 pm May 18th (Thursday)

Abstract：

In this project, we aim to understand structures in galaxies from a deconstructive perspective. In a series of papers, we have developed an accurate, efficient, and unsupervised way that extracts structures of simulated galaxies in kinematics. We successfully identify kinematically-derived bulge, disk, and halo structures that have clear physical formation mechanisms in the IllustrisTNG simulations. This study helps us understand the formation and evoultion of galaxies and their structures. And it also provides important insights into the relationship between kinematically and morphologically derived galactic structures. We found that (1) the morphologically decomposed bulges are composite structures comprising a slowly rotating bulge, an inner stellar halo, and a disky bulge; (2) kinematically defined bulges are old, but have no/weak relation with mergers, which challenges the traditional picture; (3) stellar halos formed via mergers are significantly underestimated in the traditional bulge+disk decomposition, which caused serious misleading in studies about bulges; (4) disks are likely to conserve the angular momentum of their host dark matter halos.

CV：

My main interests include the structures of galaxies, the formation and evoultion of galaxies, numerical simulations, and galactic dynamics

2011-2017 PhD research at the Shanghai Astronomical Observatory, China 

2017-2021 Post-doc research at the Kavli Institute for Astronomy and Astrophysics, Peking University (Beijing, China)

From 2021.9 Associate professor at the Xiamen University, China

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