On the Pair-Instability Supernova origin of J1010+2358
‘Asa Sk’ulad’ottir, Ioanna Koutsouridou, Irene Vanni, Anish M. Amarsi, Romain Lucchesi, Stefania Salvadori, David Aguado
arXiv:2404.19086v1 Announce Type: new
Abstract: 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 effect. 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 $(chi^2/chi^2_{rm best}approx2.3)$ 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 has not necessarily obtained any of its metals from a PISN. So the search continues for a concrete proof of the existence of zero-metallicity PISNe.arXiv:2404.19086v1 Announce Type: new
Abstract: 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 effect. 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 $(chi^2/chi^2_{rm best}approx2.3)$ 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 has not necessarily obtained any of its metals from a PISN. So the search continues for a concrete proof of the existence of zero-metallicity PISNe.