Lunch talk on Dec. 25, 2020

The Star Formation History of Early-type Galaxies -- From an [alpha/Fe] view

Speaker: Yiqing Liu（Oxford University）

Venue: Video conference

Time: 12:30 PM, Friday, Dec. 25, 2020

Abstract: 

Star formation history (SFH) is key to understand galaxy formation and evolution.  For early-type galaxies (ETGs), in particular, their SFHs also record their quenching scenarios.  Using stellar alpha-to-iron abundance ratio ([alpha/Fe]) as an indicator of star formation timescale (t_SF), I will present our work on the [alpha/Fe]-velocity dispersion relation of ETGs that extends to low masses with a range of dataset, and show a mass-dependent t_SF for most ETGs across a wide mass range on average, where more massive ETGs have shorter t_SF.  However, the [alpha/Fe] of low-mass galaxies from the highest- and lowest-density environments in the sample are more dependent on environments than galactic masses.  I will also discuss the dependences of these results on different stellar population models and approaches.  The data are from Gemini/GMOS-IFU observations, the literature, and the MaNGA survey.