Abstract

Koutsouridou
The energy distribution of the first supernovae
The nature of the first (Pop III) stars is still a mystery and the energy distribution of the first supernovae (SN) is completely unexplored. With no direct observations of Pop III stars available, researchers rely on deciphering their properties through the analysis of the abundance patterns in their long-lived descendants in the Milky Way (MW) and its dwarf satellites. However, stellar evolution models reveal that there exist degeneracies in the predicted Pop III metal yields, among the unknown Pop III masses and explosion energies, that can compicate these efforts. To address this issue, we have developed a cosmological model for the formation of a MW-analogue that, for the first time, accounts simultaneously for the initial mass function (IMF) and the energy distribution function (EDF) of Pop III stars. In this talk, we present a comparison of our model predictions to the observed properties of metal poor stars in the Galactic halo, that allows us to provide the first available constraints on the EDF of Pop III SNe. Using our model, we explore how the observed frequency (or non-detection) of descendants of specific Pop III SN types can be utilized to break the aforementioned degeneracies and provide tighter constraints on the statistical properties of Pop III stars. Within this framework, we discuss the implications of the newly discovered pair instability supernova descendant (Xing et al. 2023) for the IMF of Pop III stars.

Koutsouridou

The energy distribution of the first supernovae

The nature of the first (Pop III) stars is still a mystery and the energy distribution of the first supernovae (SN) is completely unexplored. With no direct observations of Pop III stars available, researchers rely on deciphering their properties through the analysis of the abundance patterns in their long-lived descendants in the Milky Way (MW) and its dwarf satellites. However, stellar evolution models reveal that there exist degeneracies in the predicted Pop III metal yields, among the unknown Pop III masses and explosion energies, that can compicate these efforts.
To address this issue, we have developed a cosmological model for the formation of a MW-analogue that, for the first time, accounts simultaneously for the initial mass function (IMF) and the energy distribution function (EDF) of Pop III stars.
In this talk, we present a comparison of our model predictions to the observed properties of metal poor stars in the Galactic halo, that allows us to provide the first available constraints on the EDF of Pop III SNe. Using our model, we explore how the observed frequency (or non-detection) of descendants of specific Pop III SN types can be utilized to break the aforementioned degeneracies and provide tighter constraints on the statistical properties of Pop III stars. Within this framework, we discuss the implications of the newly discovered pair instability supernova descendant (Xing et al. 2023) for the IMF of Pop III stars.

ESO — Reaching New Heights in Astronomy

Abstract