"Studying the Impact of Galaxy Interactions and Dense Environments on the Star Formation and Nuclear Activity of Galaxies at 0.5 < z < 4.5"
Ekta Shah (University of California, Davis)
Tuesday 03/10/2023 @ 14:30, Sala Antonio Sollima IV piano
Exploring the intricate interplay among galaxy interactions, dense environments, star formation, and active galactic nucleus (AGN) activity is essential for unraveling the mechanisms driving galaxy evolution. Motivated by studying these complex relations, I will start this talk by discussing the impact of galaxy interactions on the star formation rate (SFR) and AGN activity within the redshift range of 0.5 < z < 3.0 utilizing extensive observations from the CANDELS and COSMOS surveys. With one of the largest spectroscopic pair samples ever assembled, I will show the comparison of the SFR, as well as the fractions of X-ray and infrared AGN, in this pair sample relative to a carefully matched control group in terms of mass, redshift, and environment. I will present SFR enhancement and AGN enhancement results along with a comparison with results at lower redshift of z~0. Additionally, I will show a parallel analysis performed using the Illustris-TNG simulation, and make a comparative examination of the simulation results with those of the observations. In the second part of this talk, I will focus on my more recent work on the investigation of the densest environments at high redshifts, galaxy protostructures, and their influence on galaxy evolution within the redshift range of 2.5 < z < 4.5. Through the Charting Cluster Construction with VUDS and ORELSE (C3VO) survey, I have identified and characterized six massive overdensities in the ECDFS field. I will present these overdensities and their properties, as well as a preliminary analysis of the star formation rates and AGN activity observed across various environments. These results shed light on the role played by the environment in the evolution of galaxies during a time when most of the stellar mass in the universe is being assembled.