Lunch talk on Dec. 25th, 2017

The semi-analytic model of galaxy formation and size evolution of late-type galaxies

Speaker:谢利智 / Lizhi Xie(Astronomical Observatory of Trieste - INAF)

Venue:Gewu 4410
Time:12:30 PM, Monday, 25th December

Abstract:

I will present an up-to-date semi-analytic model, GAEA (arXiv: 1611.09372), which is featured with a detail chemical enrichment scheme, a 'realistic' Supernovae feedback model based on hydro-simulations, and H2-based star formation laws. I will introduce how we construct the model: the bone -- dark matter merger tree and the flesh -- sub-grid physics of galaxy formation and evolution. The model predicts good agreement with observational estimates for the stellar mass function, gas contents scaling relations, and metallicity. It fails in some aspects, e.g. star formation rate at high redshift, and quenching time scale of satellite galaxies, problems that shared by many galaxy models. Then I will highlight a study on size evolution of late-type galaxies. We compare the model predictions with observational measurements from the Hα3 and HAGGIS surveys to study the gas content and gaseous/stellar disk sizes of star forming galaxies. In particular, we focus on the differences between central/HI-normal and satellite/HI-deficient galaxies with the aim to determine when and how these differences arise. We find that the differences in HI mass and sizes between central and satellite galaxies are connected with the assembly histories of their parent dark matter halos.

Doodle:https://doodle.com/poll/8hzhix62aetrffnz