Conveners
Day 4
- Rodolfo Smiljanic
The chemical evolution of galaxies is governed by the chemical yields from stars, especially from Asymptotic Giant Branch (AGB) stars. Observations from Post-Asymptotic Giant Branch (post-AGB) stars serve as exquisite tools to quantify and understand AGB nucleosynthesis. Our studies have shown that AGB nucleosynthesis is riddled with complexities. In this talk, I will present the invaluable...
Measurements of elemental abundances and their isotope ratios allow us to perform key tests of mixing mechanisms inside stars and provide powerful diagnostics of chemical enrichment in galaxies across cosmic time. For this purpose we need large samples of stars with precise chemical abundances over a full range of metallicities and other stellar atmospheric parameters, a full range of masses,...
Dwarf galaxies and larger satellite galaxies are ideal laboratories to study the earliest chemical evolution, different nucleosynthetic channels, dark matter structure, and hierarchical galaxy formation. The Milky Way has dozens of satellites which can be studied in far greater detail than their more distant counterparts. With upcoming large spectroscopic surveys such as 4MOST and WEAVE, these...
We investigate the contribution of sub-Chandrasekhar mass Type Ia supernovae to the chemical enrichment of the Gaia Sausage galaxy, the progenitor of a significant merger event in the early life of the Milky Way. Using a combination of data from Nissen & Schuster (2010), the 3rd GALAH data release (with 1D NLTE abundance corrections) and APOGEE data release 16, we fit analytic chemical...
I will discuss the potential for HRMOS in studying the stars that are escaping from globular clusters into the halo field through streams or extratidal structures. These stars allow us to address questions of globular cluster origins, abundance anomalies, and chemical tagging, as well as dynamics, mass loss, and dark matter. The large-scale spectroscopic surveys planned for the 2020s will...
The halo of our Milky Way is scarred by galaxy formation in the form of stellar streams. These streams are a uniquely powerful tool for understanding the building blocks of the Milky Way’s stellar halo, the mass and shape of the Milky Way’s halo, and ultimately the nature of dark matter. Each stream is the remnant of a dwarf galaxy or globular cluster; the former are especially interesting as...
The homogeneous comparison between the chemical composition of the Milky Way (MW) and its more massive satellites (Large Magellanic Cloud - LMC and Sagittarius - Sgr) reveals that the latter galaxies have different chemical abundances with respect to the MW stars for almost all the species. In particular the largest difference is measured for [V/Fe] and [Zn/Fe], reaching up to 0.5/0.7 dex for...
The properties of the first stars remain unknown. The chemistry of relic environments, enriched only by the supernovae of the first (Pop III) stars, may offer the best opportunity to uncover their properties (e.g. mass distribution and explosion energies). In this talk, I will present the analysis of two of the most chemically near-pristine gas reservoirs at a redshift z~3 observed using a...
Modern-day machine learning generative models allow us to directly model the distribution of the observed spectroscopic data, even when the stellar labels are absent. In recent years, we have seen the explosion of studies in terms of supervised machine learning. However, the exploration of unsupervised generative models in stellar spectroscopy is, unfortunately, lagging behind. In this talk, I...
High-resolution spectroscopic surveys of the Milky Way have entered the Big Data regime, and have opened avenues for solving outstanding questions in Galactic Archaeology. However, exploiting their full potential is limited by complex systematics, whose characterization has not received much attention in modern spectroscopic analyses. We present a novel method to disentangle the component of...
