The Pristine survey – XIX. Cu and Zn abundances in metal-poor giants

Caffau, E.; Lombardo, Linda; Mashonkina, L.; Sitnova, T.; Bonifacio, P.; Pinto, A. M. Matas; Kordopatis, G.; Sestito, Federico; Aguado, David S.; Salvadori, Stefania; Spite, M.; François, P.; Sbordone, L.; Mucciarelli, A.; Martín, Nicolás F.; Fernández-Alvar, Emma; Hernández, J. I. González

doi:10.1093/mnras/stac3372

Cited by 6 publications

(4 citation statements)

References 88 publications

(70 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Cu i line at 578.2 nm provides a negative [Cu/Fe] ratio ([Cu/Fe] = −0.37 dex), but this is known to be a NLTE effect (see Caffau et al 2023). The star is slightly enhanced in Zn ([Zn/Fe] = 0.19 dex) and in Zr ([Zr/Fe] = 0.34 dex).…”

Section: Abundancesmentioning

confidence: 99%

High speed stars

Caffau,

Bonifacio,

Monaco

et al. 2024

A&A

Self Cite

View full text Add to dashboard Cite

The Gaia satellite has provided the community with three releases containing astrometrical and photometric data as well as by products, such as stellar parameters and variability indicators. By selecting in the Gaia database, one can select stars with the requested characteristics, such as high speed. At present any selection is based on available Gaia releases including a subset of the observations. This, for some stars, can show some limitations, for example there is still not a sufficient number of observations to detect binarity. We investigated a star selected in Gaia EDR3 for its high speed that appears unbound to the Galaxy. We requested high-quality spectra to derive more information on the star. From the spectroscopic investigation we confirm the low metallicity content of the star, and we derive a detailed chemical composition. The star is poor in carbon and very rich in oxygen: (C+N+O)/Fe =+0.65. From the two spectra observed we conclude that the star is in a binary system and from the investigation of the ionisation balance we derive that the star is closer than implied by the Gaia DR3 parallax, and thus has a a lower intrinsic luminosity. The star is probably still unbound, but there is the possibility that it is bound to the Galaxy. Its low carbon abundance suggests that the star was formed in a dwarf galaxy.

show abstract

Section: Abundancesmentioning

confidence: 99%

High speed stars

Caffau,

Bonifacio,

Monaco

et al. 2024

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…After decades of dedicated searches (e.g., Beers & Christlieb 2005;Aoki et al 2014;Caffau et al 2023) and development of novel techniques to pinpoint PISN descendants (Salvadori et al 2019;Aguado et al 2023), in 2023 June a remarkable Galactic halo star with very strong odd-even effects has finally been identified by the LAMOST survey (Xing et al 2023). This very metal-poor (VMP) star, J1010+2358, has [Fe/H] ≈ − 2.42 ± 0.12, and exhibits extremely low abundances of odd elements such as Na and Sc.…”

Section: Introductionmentioning

confidence: 99%

“…Ultimately, despite the identification of stars that might have been partially imprinted by PISNe (Aoki et al 2014;Salvadori et al 2019;Aguado et al 2023;Caffau et al 2023), J1010 +2358 represents so far the unique candidate of a pure PISN descendant. But is the abundance pattern of J1010+2358 only consistent with mono-enrichment by a single 260 M e PISN, or do other solutions exist?…”

Section: Introductionmentioning

confidence: 99%

True Pair-instability Supernova Descendant: Implications for the First Stars’ Mass Distribution

Koutsouridou,

Salvadori,

Skúladóttir

2024

ApJL

Self Cite

View full text Add to dashboard Cite

The initial mass function (IMF) of the first Population III (Pop III) stars remains a persistent mystery. Their predicted massive nature implies the existence of stars exploding as pair-instability supernovae (PISNe), but no observational evidence had been found. Now, the LAMOST survey claims to have discovered a pure PISN descendant, J1010+2358, at [Fe/H] = − 2.4. Here we confirm that a massive 250–260 M ⊙ PISN is needed to reproduce the abundance pattern of J1010+2358. However, the PISN contribution can be as low as 10%, since key elements are missing to discriminate between scenarios. We investigate the implications of this discovery for the Pop III IMF, by statistical comparison with the predictions of our cosmological galaxy formation model, NEFERTITI. First, we show that the nondetection of mono-enriched PISN descendants at [Fe/H] < − 2.5 allows us to exclude (i) a flat IMF at a 90% confidence level; and (ii) a Larson-type IMF with characteristic mass m ch/M ⊙ > 191.16x − 132.44, where x is the slope, at a 75% confidence level. Second, we show that if J1010+2358 has only inherited <70% of its metals from a massive PISN, no further constraints can be put on the Pop III IMF. If, instead, J1010+2358 will be confirmed to be a nearly pure (>90%) PISN descendant, it will offer strong and complementary constraints on the Pop III IMF, excluding the steepest and bottom-heaviest IMFs: m ch/M ⊙ < 143.21x − 225.94. Our work shows that even a single detection of a pure PISN descendant can be crucial to our understanding of the mass distribution of the first stars.

show abstract

“…Many efforts have been dedicated to seek out these unique PISN fingerprints (see Salvadori et al 2019;Aguado et al 2023;Caffau et al 2023) and finally one possible pure PISN descendant has been found in the LAMOST survey (Xing et al 2023). If predominantly enriched by PISN (see Jeena et al 2024), this unique star will provide us with the first tight constraints on the initial mass function (IMF) of Pop III stars (Koutsouridou et al 2024).…”

Section: Introductionmentioning

confidence: 99%

Chemical Diagnostics to Unveil Environments Enriched by First Stars

Vanni,

Salvadori,

D’Odorico

et al. 2024

ApJL

Self Cite

View full text Add to dashboard Cite

Unveiling the chemical fingerprints of the first (Population III, hereafter Pop III) stars is crucial for indirectly studying their properties and probing their massive nature. In particular, very massive Pop III stars explode as energetic pair-instability supernovae (PISNe), allowing their chemical products to escape in the diffuse medium around galaxies, opening the possibility to observe their fingerprints in distant gas clouds. Recently, three z > 6.3 absorbers with abundances consistent with an enrichment from PISNe have been observed with JWST. In this Letter, we present novel chemical diagnostics to uncover environments mainly imprinted by PISNe. Furthermore, we revise the JWST low-resolution measurements by analyzing the publicly available high-resolution X-Shooter spectra for two of these systems. Our results reconcile the chemical abundances of these absorbers with those from literature, which are found to be consistent with an enrichment dominated (>50% metals) by normal Pop II SNe. We show the power of our novel diagnostics in isolating environments uniquely enriched by PISNe from those mainly polluted by other Pop III and Pop II SNe. When the subsequent enrichment from Pop II SNe is included, however, we find that the abundances of PISN-dominated environments partially overlap with those predominantly enriched by other Pop III and Pop II SNe. We dub these areas confusion regions. Yet, the odd–even abundance ratios [Mg,Si/Al] are extremely effective in pinpointing PISN-dominated environments and allowed us to uncover, for the first time, an absorber consistent with a combined enrichment by a PISN and another Pop III SN for all the six measured elements.

show abstract

The Pristine survey – XIX. Cu and Zn abundances in metal-poor giants

Cited by 6 publications

References 88 publications

High speed stars

High speed stars

True Pair-instability Supernova Descendant: Implications for the First Stars’ Mass Distribution

Chemical Diagnostics to Unveil Environments Enriched by First Stars

Contact Info

Product

Resources

About