Astro Lunch Seminar

Speaker: Po-Feng Wu (NAOJ)
Title: Tracing galaxy evolution with deep spectroscopic survey
Date: Tue, Jan 21, 2020, 12:00 - 13:00
Place: Seminar Room A
Related File: 2494.pdf
Abstract: The stars in galaxies hold the fossil record of galaxy evolution. The SDSS legacy survey provides a large number of galaxy spectra that characterize the stellar components of galaxies, e.g., stellar kinematics, formation histories, and metal contents in stars, however, mainly for galaxies in the nearby universe. In this talk, I will present the recent campaign, the LEGA-C spectroscopic survey on the VLT-8m that obtains rest-frame optical spectra of ~3000 massive galaxies at z~1, with spectral resolution and signal-to-noise ratio matching the SDSS legacy survey at z~0.1.

I will first give an overview of the survey: the design, the product, and the data release. From the deep spectra, we have characterized the kinematic, ages, and formation histories of the stellar component of galaxies at z~1. We infer the evolution of the galaxy population in the last 7 Gyrs by comparing the LEGA-C and SDSS surveys. Combining with ancillary data, I will show that the deep spectra further give insight on the lives of galaxies: how the star-formation stops and the quiescence is maintained, as well as the evolution after the cessation of star-formation of galaxies at z~1. The coming multi-object spectrographs on 8-m class telescopes offer new opportunities to explore this new parameter space for galaxies in the even earlier universe.