BEGIN:VCALENDAR VERSION:2.0 PRODID:-// 1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT DTSTART;TZID=Atlantic/Canary:20230302T123000 DTEND;TZID=Atlantic/Canary:20230302T133000 UID:iactalks-1664 X-WR-CALNAME: IAC Talks: Open Astronomy Seminars X-ORIGINAL-URL: /Talks/view/1664 CREATED:2023-03-02T12:30:00+00:00 X-WR-CALDESC: IAC Talks upcomming talks SUMMARY:Early-type galaxies: instructions to build them through mergers DESCRIPTION:Early-type galaxies: instructions to build them through mergers \nDr. Carlo Cannarozzo\n\n \nEarly-type galaxies: instructions to bui ld them through mergers\nMassive 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 remnan ts of a complex stellar mass assembly history marked by several mergers, which are the consequence of the underlying hierarchical assembly of thei r host dark matter halos. In this talk, I will deal mainly with the merger-driven evolution of ETGs. Firstly, I will illustrate a compa rison between observed ETGs from the MaNGA survey and simulated galaxies from the IllustrisTNG cosmological simulation suite. The aim of this stud y is to provide an interpretative scenario of the stellar mass assembly h istory of observed present-day ETGs, comparing the radial distributions o f their stellar properties with those of simulated galaxies, in which it is possible to disentangle the contribution of stars formed in situ (i.e. within the main progenitor galaxy) and stars formed ex situ (i.e. in oth er galaxies) and then accreted through mergers. Then, I will describ e how the scaling relation between the stellar mass and stellar velocity dispersion in ETGs evolves across cosmic time. Specifically, by extendin g the results of Cannnarozzo, Sonnenfeld & Nipoti (2020), I model the aforementioned relation through a Bayesian hierarchical approach, consid ering ETGs with log(M∗/M⊙) > 9 over the redshift range 0 ≲ z ≲ 4. Together with a new characterisation of the relation, I rec onstruct the back-in-time evolutionary pathways of individual ETGs on the stellar mass-velocity dispersion plane to answer the question “how did high-redshift ETGs assemble through cosmic time to reach the functio nal form of the relation in the present-day Universe?“.\nAfter the main topic, if time permits, I would like to spend a few minutes presenti ng another extra content (below you can find the title and a brief abstra ct of this further content). Feel free to include it or not in the announ cement mail.\nEXTRA - Inferring the Dark Matter halo mass in galaxies from other observables with Machine Learning\nIn the context of the gala xy-halo connection, it is widely known that the Dark Matter (DM) halos sh ow correlations with some physical properties of the hosted galaxy: the m ost well-known relation is the so-called Stellar-to-Halo-Mass Relation. H owever, we know that there are several other empirical relations among ga laxy properties, involving, for example, the stellar mass, the gas and st ellar metallicities, the black hole mass, etc. Given the complexity of th e problem and the high number of galaxy properties that might be related to DM halos, the study of the galaxy-halo connection can be approached by relying on machine learning techniques to shed light on this intricate n etwork of relations. With the aim of inferring the DM halo mass and then finding a unique functional form able to link the halo mass to other obse rvables in real galaxies, I rely on the state-of-the-art Explainable Boos ting Machine, a novel implementation of generalised additive models with pairwise interactions, training a model on the IllustrisTNG simulation su ite at different redshift.\n \n \n \nYoutube933518 END:VEVENT END:VCALENDAR