2024/04/29 by Skúladóttir, Ása, Koutsouridou, Ioanna, Vanni, Irene +4 · 1 citation
#Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2404.19086
The first (Pop III) stars formed only out of H and He and were likely more massive than present-day stars. Massive Pop III stars in the range 140-260 M_\odot are predicted to end their lives as pair-instability supernovae (PISNe), enriching the environment with a unique abundance pattern, with high ratios of odd to even elements. Recently, the most promising candidate for a pure descendant of a zero-metallicity massive PISN (260 M\odot) was discovered by the LAMOST survey, the star J1010+2358. However, the key elements to verify the high PISN contribution, C and Al, were missing from the analysis. To rectify this, we obtained and analyzed a high-resolution VLT/UVES spectrum, correcting for 3D and/or non-LTE effects. Our measurements of both C and Al give much higher values (~1 dex) than expected from a 260 M\odot PISN. Furthermore, we find significant discrepancies with the previous analysis, and therefore a much less pronounced odd-even pattern. Thus, we show that J1010+2358 cannot be a pure descendant of a 260 M\odot PISN. Instead, we find that the best fit model consists of a 13 M\odot Pop II core-collapse supernova combined with a Pop III supernova. Alternative, less favoured solutions (χ2/χ2\rm best≈2.3) include a 50% contribution from a 260 M\odot PISN, or a 40% contribution from a Pop III type Ia supernova. Ultimately, J1010+2358 is certainly a unique star giving insights into the earliest chemical enrichment, however, this star is not a pure PISN descendant.