Mohammadreza Ayromlou

Max Planck Institute for Astrophysics

Galaxy formation with L-Galaxies: galaxy evolution meets large-scale structure

Abstract: I first describe the standard theory of galaxy formation and evolution and introduce different kinds of galaxy formation modeling, including semi-analytical models and hydrodynamical simulations.

I then introduce a local background environment (LBE) estimator to quantify environment locally for all galaxies within cosmological simulations. Analyzing the LBE properties, I show that there should be no boundary for dark matter haloes when modeling galaxy evolution. I use the time-evolving LBE of galaxies to develop a method to better account for environmental processes within the Munich semi-analytical model of galaxy formation, L-Galaxies. Using this new method, I remove the artificial halo boundary and extend environmental processes to all galaxies in the simulation. I recalibrate the updated model using a Markov Chain Monte Carlo (MCMC) method and a few observational constraints. By comparing our results to data on galaxy properties in different environments from different surveys (e.g. SDSS, HSC), I demonstrate that the updated model significantly improves the agreement with the observations. Overall, in the vicinity of massive dark matter haloes, the new model produces stronger environmental dependencies, better recovering observed trends with halocentric distance up to scales much beyond the halo virial radius. This is likely to influence the correlations between galaxies up to tens of Megaparsecs. This presentation is based on the following papers: arXiv 1903.01988, 2004.14390, 2011.05336

یکشنبه 20 تیر 1400، ساعت 19:00

Sunday 11 July 2021 – 19:00 Tehran Time

اتاق سمینار مجازی –Virtual Seminar Room

https://vc.sharif.edu/ch/cosmology

گزینه ورود به صورت مهمان – Enter as a Guest