Navó Perez, Gerard (2024)
Core-collapse supernovae: reduced nuclear networks and equations of state.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00027687
Dissertation, Erstveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
Massive stars end their life in violent explosive events that are triggered by the collapse of the iron core, the so-called core-collapse supernovae (CCSNe). CCSNe host a large variety of thermodynamic conditions, from cold low-density regions in the external layers of the collapsing star to the hot and very dense nascent proto-neutron star (PNS). Nuclear physics is a key ingredient to determine the evolution of CCSNe. At high densities, the strong interaction governs the equation of state (EOS), which has large impact on the dynamics. Nevertheless, the EOS of dense matter is not fully understood. Numerical simulations are crucial to understand, and explore, the mechanisms involved in the explosion. Thus, we use CCSNe simulations as laboratories to study the impact of several nuclear matter properties on the dynamics of the PNS and the explosion. At low densities, nuclear reactions describe the nucleosynthesis that takes place in the events, which play an essential role in the chemical evolution of the universe. Unfortunately, CCSN simulations are very computationally expensive and, therefore, they need to employ approximations. At low densities, they often consider a very simplified nuclear composition. In the first part of the thesis, we investigate the impact of the composition and the energy released by nuclear reactions at low temperatures. We implement two reduced nuclear reactions networks and study their impact in the simulation. The largest evolves the main species synthesized during the explosion. We perform one- and two-dimensional simulations where we test the networks and study the effects on the dynamics of the explosion and the nucleosynthesis. We find that sufficiently large reduced nuclear networks are necessary for more accurate feedback of the nuclear energy generation, neutrino absorption, and nucleosynthesis. In the second part of the thesis, we study the effects of nuclear matter properties in CCSNe. We perform one-dimensional models using several EOSs that systematically vary the slope parameter, symmetry energy, incompressibility, and the density exponent of the energy density functional. We find that a higher slope parameter produces a slower PNS contraction, a less energetic shock, and a less compact remnant. In addition, our results suggest that a low incompressibilty causes a faster collapse, much higher central densities at bounce, and is less likely to revive the shock. Finally, we show the early evolution stage of a state-of-the-art 3D CCSN simulation including a reduced nuclear reaction network, that will become a benchmark for future sytematic studies in one and two dimensions. We describe its main characteristics and conclude that it will produce a successful explosion.
Typ des Eintrags: | Dissertation | ||||
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Erschienen: | 2024 | ||||
Autor(en): | Navó Perez, Gerard | ||||
Art des Eintrags: | Erstveröffentlichung | ||||
Titel: | Core-collapse supernovae: reduced nuclear networks and equations of state | ||||
Sprache: | Englisch | ||||
Referenten: | Arcones, Prof. Dr. Almudena ; Aloy, Prof. Dr. Miguel Ángel | ||||
Publikationsjahr: | 24 Juli 2024 | ||||
Ort: | Darmstadt | ||||
Kollation: | xiii, 119 Seiten | ||||
Datum der mündlichen Prüfung: | 6 November 2023 | ||||
DOI: | 10.26083/tuprints-00027687 | ||||
URL / URN: | https://tuprints.ulb.tu-darmstadt.de/27687 | ||||
Kurzbeschreibung (Abstract): | Massive stars end their life in violent explosive events that are triggered by the collapse of the iron core, the so-called core-collapse supernovae (CCSNe). CCSNe host a large variety of thermodynamic conditions, from cold low-density regions in the external layers of the collapsing star to the hot and very dense nascent proto-neutron star (PNS). Nuclear physics is a key ingredient to determine the evolution of CCSNe. At high densities, the strong interaction governs the equation of state (EOS), which has large impact on the dynamics. Nevertheless, the EOS of dense matter is not fully understood. Numerical simulations are crucial to understand, and explore, the mechanisms involved in the explosion. Thus, we use CCSNe simulations as laboratories to study the impact of several nuclear matter properties on the dynamics of the PNS and the explosion. At low densities, nuclear reactions describe the nucleosynthesis that takes place in the events, which play an essential role in the chemical evolution of the universe. Unfortunately, CCSN simulations are very computationally expensive and, therefore, they need to employ approximations. At low densities, they often consider a very simplified nuclear composition. In the first part of the thesis, we investigate the impact of the composition and the energy released by nuclear reactions at low temperatures. We implement two reduced nuclear reactions networks and study their impact in the simulation. The largest evolves the main species synthesized during the explosion. We perform one- and two-dimensional simulations where we test the networks and study the effects on the dynamics of the explosion and the nucleosynthesis. We find that sufficiently large reduced nuclear networks are necessary for more accurate feedback of the nuclear energy generation, neutrino absorption, and nucleosynthesis. In the second part of the thesis, we study the effects of nuclear matter properties in CCSNe. We perform one-dimensional models using several EOSs that systematically vary the slope parameter, symmetry energy, incompressibility, and the density exponent of the energy density functional. We find that a higher slope parameter produces a slower PNS contraction, a less energetic shock, and a less compact remnant. In addition, our results suggest that a low incompressibilty causes a faster collapse, much higher central densities at bounce, and is less likely to revive the shock. Finally, we show the early evolution stage of a state-of-the-art 3D CCSN simulation including a reduced nuclear reaction network, that will become a benchmark for future sytematic studies in one and two dimensions. We describe its main characteristics and conclude that it will produce a successful explosion. |
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Status: | Verlagsversion | ||||
URN: | urn:nbn:de:tuda-tuprints-276871 | ||||
Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 530 Physik | ||||
Fachbereich(e)/-gebiet(e): | 05 Fachbereich Physik 05 Fachbereich Physik > Institut für Kernphysik 05 Fachbereich Physik > Institut für Kernphysik > Theoretische Kernphysik 05 Fachbereich Physik > Institut für Kernphysik > Theoretische Kernphysik > Kernphysik und Nukleare Astrophysik |
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TU-Projekte: | DFG|SFB1245|B06 Arcones SFB1245 DFG|SFB1245|B06_B07_SFB1245 |
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Hinterlegungsdatum: | 24 Jul 2024 12:23 | ||||
Letzte Änderung: | 25 Jul 2024 06:39 | ||||
PPN: | |||||
Referenten: | Arcones, Prof. Dr. Almudena ; Aloy, Prof. Dr. Miguel Ángel | ||||
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 6 November 2023 | ||||
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