The evolution of the SFRs and stellar masses of galaxies in the Past 13 billion years----中国科学院紫金山天文台

Seminar Title	The evolution of the SFRs and stellar masses of galaxies in the Past 13 billion years

Speaker:	Dr. Antonios Katsianis

Affiliation:	( Li Zhengdao research institute, SJTU)

When	Friday morning, Sep. 11, 10:00 a.m.

Where:	Room 516 No.5 building , Xianlin campus (PMO, CAS)
	Welcome to Attend

	( PMO Academic Committee & Academic Circulating committee)

Abstract: The observed star formation rate - stellar mass relation of galaxies and the star formation rate function have been representing two canvases for our current knowledge of galaxy formation and evolution. However, serious tension between different groups that use different techniques and indicators is reported in the literature (e.g. Katsianis et al. 2016, 2020). Employing the Evolution and Assembly of GaLaxies and their Environments (EAGLE) combined with the radiative transfer code SKIRT we demonstrate that the inconsistency between different groups is significantly decreased when similar techniques are used to obtain galaxy properties (Katsianis et al. 2020). In addition, we propose that mimicking the methodologies used in observational studies is a key element for their comparison with cosmological simulations and can possibly reconcile the long-standing tension between them. In addition, we focus on the scatter (σsSFR) of the specific star formation rates of galaxies and study its dependence on stellar mass (M？) and redshift. We employ the EAGLE simulations and the Galaxy And Mass Assembly (GAMA) observations in order to study the shape of the σsSFR-M？ relation at z ~ 0 - 4. We suggest that the relation evolves with time and the dispersion depends strongly on stellar mass, contrary to the usual notion that the scatter is constant (~ 0.3 dex) and not evolving. Our study points to an evolving U-shape form for the σsSFR-M？relation with the scatter being minimal at a characteristic mass M？ of log10(M*) ~ 9.5 M⊙, increasing both at lower and higher masses. Last, alongside presenting limitations in observational studies I focus on some serious shortcomings of today state-of-the-art simulations.