Detalles de publicación
PP 024036
On the Pair-Instability Supernova origin of J1010+2358
(1)University of Florence
(2)Uppsala University
(3)IAC
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⊙ are predicted to end their lives as pairinstability 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⊙) 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 high-resolution VLT/UVES spectra. Our measurements of both C and Al give much higher values (∼ 1 dex) than expected from a 260 M⊙ 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⊙ PISN. Instead,
we find that the best fit model consists of a 13 M⊙ Pop II core-collapse supernova combined with a
Pop III supernova. Alternative, less favored solutions (χ2/χ2best ≈ 2.3) include a 50% contribution from
a 260M⊙ 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.
stars. Massive Pop III stars in the range 140 − 260 M⊙ are predicted to end their lives as pairinstability 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⊙) 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 high-resolution VLT/UVES spectra. Our measurements of both C and Al give much higher values (∼ 1 dex) than expected from a 260 M⊙ 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⊙ PISN. Instead,
we find that the best fit model consists of a 13 M⊙ Pop II core-collapse supernova combined with a
Pop III supernova. Alternative, less favored solutions (χ2/χ2best ≈ 2.3) include a 50% contribution from
a 260M⊙ 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.