COLLOQUIUM: Dr. Moritz Reichert (University of Valencia)
Wann: Mi, 19.06.2024, 14:00 Uhr bis 15:30 Uhr
Wo: Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Bibliothek
Exploring Alternative Pathways: Magnetorotationally Driven Supernovae and the Origins of Heavy Elements
In this talk, I provide a comprehensive overview of the formation of heavy elements in the universe, known as r-process elements. While the scenario of two merging neutron stars has often been a primary focus in literature, numerous observations remain challenging to explain with neutron star mergers alone. Consequently, I explore an alternative astrophysical scenario for the synthesis of heavy elements. One such scenario involves magnetorotationally driven supernovae - supernovae that involve extreme magnetic fields. They have been hypothesized as an additional channel for r-process element production over the universe's lifespan. In my presentation, I will highlight their possible contribution to the origins of heavy elements, employing a dual approach of observational and theoretical analysis.
From an observational standpoint, I will examine the nucleosynthetic fingerprints present in the atmospheres of stars within dwarf spheroidal galaxies, providing insights into the nucleosynthesis processes at play. These galaxies offer unique insights due to their distinct histories of star formation and enrichment events. The direct association of especially r-process enriched stars with specific episodes of star formation in these galaxies contrasts with Galactic stars, often originating from accretion processes. Thus, this exploration reveals a direct connection between the properties of dwarf galaxies and the events hosting the formation of heavy elements.
From a theoretical perspective, a thorough understanding of magnetorotationally driven supernovae necessitates hydrodynamical simulations.
My analysis focuses on the nucleosynthesis of 3D models incorporating a sophisticated neutrino transport. Despite inherent uncertainties, such as variations in magnetic field strength and topology, we systematically vary these parameters to elucidate their impact on r-process element synthesis. Notably, we find that strong magnetic fields and large-scale dipoles facilitate the synthesis of heavy elements. Importantly, this observation holds true irrespective of uncertainties of the nuclear physics input.
We conclude that magnetorotational supernovae emerge as promising candidates for explaining stars with lower levels of heavy-element enrichment. Through a combination of observational insights and theoretical investigations, we aim to deepen our understanding of the origins of heavy elements.
Talk in presence and via Zoom:
https://uni-hamburg.zoom.us/j/66006535328?pwd=aGkrSjJIYmZjK0VpYlpGL0ZrdHg2UT09
Meeting ID: 660 0653 5328
Passcode: 20658852