In recent years a major effort was dedicated to collecting large data sets of high-quality spectra of stars in the Milky Way and to improving data analysis pipelines with machine learning and artificial intelligence. This allowed us to efficiently obtain atmospheric parameters and chemical abundances for hundreds of thousand of stars. However, less effort was …
The importance of chemical characterization for studying the history of the Milky Way (MW) and its accretion events is well established. However, challenges remain, especially at lower metallicities. N-capture elements carry insightful information concerning chemical evolution, but their distribution in very MW metal-poor stars shows a large dispersion in chemical space that chemical evolution models …
The goal of my thesis is to present an analysis of the ASASSN survey core-collapse supernova (CCSN) environments and occurrence rates, to constrain the progenitor stars related to each CCSN subtype. For the first project, I analyzed a sample of 111 galaxies observed by the All-weather MUse Supernova Integral field Nearby Galaxies survey (AMUSING) that …
Characterizing the Environments and Occurrence Rates of Core-Collapse Supernovae Read More »
Supernovae are among the most energetic explosions in the Universe, they are extremely important for studying high energy physics, stellar evolution and mass-loss processes, compact objects, cosmology, nucleosynthesis, and galaxy evolution. Optical transient surveys such as ZTF, ATLAS, ASAS-SN now find thousands of supernovae and other explosive transients per year, and these numbers will increase …
Chemical abundances of long-lived stars can be used as fossil records of Galactic history, hence serving as a proxy for the Milky Way’s DNA. We use this idea to develop phylogenetic tools to study the evolution of galaxies using chemical abundances as the heritable trait. This means closely working with evolutionary biologists and mathematicians since …
Stellar spectroscopy is the technique to determine stellar parameters and chemical abundances of stars, and relies on the modeling of stellar atmospheres which are based on simplistic (therefore uncertain) assumptions. The Gaia Benchmark Stars are well-known stars from which information about their structure beyond the spectra can be obtained (interferometric and astrometric measurements). These stars …
The Milky Way Mapper of the SDSS-V will survey more than one million stars in the Milky Way providing a wealth of information about the chemical composition of our Galaxy. That information however can only be accurate and precise if validated against a set of reference stars. At UDP we lead the assembly and analysis …
SDSS-V Milky Way Mapper: The Validation sample for stellar parameters Read More »
The Local Volumen Mapper is an IFU survey mapping out the Milky Way and the Magellanic Clouds using a new facility located at the Las Campanas Observatory. Science commissioning and verification started in July 2023 and we aim to move into survey mode by October/November 2023, with the survey lasting ~3.5 years. E. Johnston is …
SDSS-V Local Volume Mapper: Survey Operations Scientist Read More »
Nuclear Star Clusters (NSCs) lie at the centers of many galaxies, but their formation and growth mechanisms are still uncertain. For example, current theories propose that they could form in situ from gas that is funneled into the center of the galaxy, while other theories suggest that they originated as globular clusters further out in …
Investigating the Role of Nuclear Star Clusters in Galaxy Mass Assembly Read More »