Charting the Back-in-Time Evolution of the Stellar Mass–Velocity Dispersion Relation for Early-Type Galaxies
Massive early-type galaxies (ETGs) are “red and dead” systems mainly composed of old and metal-rich stellar populations. In a cosmological context, present-day ETGs are believed to be the remnants of a complex stellar mass assembly history marked by several mergers, which are the consequence of the underlying hierarchical assembly of their host dark matter halos. In this talk, I will deal with the merger-driven evolution of ETGs, describing how the scaling relation between stellar mass and stellar velocity dispersion evolves across cosmic time, and how the stellar populations of progenitor galaxies settled into the final remnants. Specifically, by extending the results of Cannnarozzo, Sonnenfeld & Nipoti (2020), I have been modelling the aforementioned relation through a Bayesian hierarchical approach, considering ETGs with log(M∗/M⊙) ≳ 9 over the redshift range 0 ≲ z ≲ 4. Together with a new characterisation of the relation, I have been reconstructing the back-in-time evolutionary pathways of individual ETGs to answer the question “how did high-redshift ETGs assemble through cosmic time to reach the functional form of the relation in the present-day Universe?“.
