The Jina Reaclib Database: Its Recent Updates and Impact on Type-I X-Ray Bursts

Cyburt, Richard H.; Amthor, A. M.; Ferguson, Ryan; Meisel, Z.; Smith, K.; Warren, S.; Heger, Alexander; Hoffman, Robert D.; Rauscher, T.; Sakharuk, Alexander; Schatz, H.; Thielemann, Friedrich‐Karl; Wiescher, M.

doi:10.1088/0067-0049/189/1/240

Cited by 965 publications

(881 citation statements)

References 157 publications

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“…Instead, one-zone simulations-although constituting a further simplification, allow studying the nucleosynthesis that may be possible in this event in isolation. The dynamic NuGrid network includes as required up to 5234 isotopes with associated rates from JINA Reaclib V1.1 (Cyburt et al 2010) and other additional sources (see Pignatari et al 2016). The general strategy is to approximate the nucleosynthesis through a series of three one-zone calculations which start with H burning followed by He burning and finally, we add in the last step a small amount of H to the partially completed He-burning nucleosynthesis calculation to estimate the nucleosynthesis due to H ingestion.…”

Section: Nucleosynthesis Calculationsmentioning

confidence: 99%

Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313−6708 and the most iron-poor stars

Clarkson

Herwig

Pignatari

2017

Monthly Notices of the Royal Astronomical Society: Letters

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We have investigated a highly energetic H-ingestion event during shell He burning leading to H-burning luminosities of log(L H /L ) ∼ 13 in a 45M Pop III massive stellar model. In order to track the nucleosynthesis which may occur in such an event, we run a series of single-zone nucleosynthesis models for typical conditions found in the stellar evolution model. Such nucleosynthesis conditions may lead to i-process neutron densities of up to ∼ 10 13 cm −3 . The resulting simulation abundance pattern, where Mg comes from He burning and Ca from the i process, agrees with the general observed pattern of the most iron-poor star currently known, SMSS J031300.36-670839.3. However, Na is also efficiently produced in these i process conditions, and the prediction exceeds observations by ∼ 2.5dex. While this probably rules out this model for SMSS J031300.36-670839.3, the typical i-process signature of combined He burning and i process of higher than solar [Na/Mg], [Mg/Al] and low [Ca/Mg] is reproducing abundance features of the two next most iron-poor stars HE 1017-5240 and HE 1327-2326 very well. The i process does not reach Fe which would have to come from a low level of additional enrichment. i process in hyper-metal poor or Pop III massive stars may be able to explain certain abundance patterns observed in some of the most-metal poor CEMP-no stars.

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Section: Nucleosynthesis Calculationsmentioning

confidence: 99%

Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313−6708 and the most iron-poor stars

Clarkson

Herwig

Pignatari

2017

Monthly Notices of the Royal Astronomical Society: Letters

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“…For the 6 Li case, the THM analysis of [34] gives S(0)=3.44±0.39MeV barns and U e =355±100 eV. The THM reaction rate deviates from ∼5% to ∼15% as the temperature decreases from 1 down to 10 −2 T 9 , if compared with the evaluation of [35] (left panel of Fig.1). To evaluate the astrophysical implications of these results, the FRANEC code has been used for pre-main sequence (PMS) models since the surface 6 Li is essentially burned in this stellar phase [36].…”

Section: The 11 B(pα 0 ) 8 Be Reaction: Main Resultsmentioning

confidence: 89%

Lithium and boron burning S(E)-factor measurements at astrophysical energies via the Trojan Horse Method

Lamia

Spitaleri

Pizzone

et al. 2014

EPJ Web of Conferences

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Abstract. The residual amount of light elements lithium, beryllium and boron (LiBeB) abundances in stellar atmospheres has been largely accepted as one of the most powerful probes for understanding stellar structure and mixing phenomena. They are in fact gradually destroyed at different depths of stellar interior mainly by (p,α), thus their fate in stars is an incomparable tool for studying mixing processes. In order to avoid extrapolation procedures on the available direct S(E)-factor measurements, the Trojan Horse Method (THM) has been developed, allowing one to measure the bare nucleus S(E)-factor for astrophysically relevant reactions without experiencing Coulomb penetrability effects. Here, a summary on the recent 6,7 Li and 11 B TH investigations will be given and the corresponding results discussed.

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“…In this study, the codes are used to follow the nuclear processing of a single zone with given initial composition under conditions of fixed temperature, density and neutron density. The nuclear network used for this project contains the 5442 isotopes and 45831 reactions from the JINA Reaclib V0.5 database [2]. In more recent releases, neutron-capture reaction rates from KADoNiS v0.2 [3] are included and refitted to eliminate blow-ups at low temperatures and to match the theory at higher temperatures (JINA Reaclib label kd02).…”

Section: Methodsmentioning

confidence: 99%

Carbon-Enhanced Metal-Poor Stars and the Need for an Intermediate Neutron Capture Process

Stancliffe¹,

Hampel²,

Lugaro³

et al. 2017

Proceedings of the 14th International Symposium on Nuclei in the Cosmos (NIC2016)

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Carbon-enhanced metal-poor (CEMP) stars in the Galactic Halo display enrichments in heavy elements associated with either the s (slow) or the r (rapid) neutron-capture process (e.g., barium and europium respectively), and in some cases they display evidence of both. The abundance patterns of these CEMP-s/r stars, which show both Ba and Eu enrichment, are particularly puzzling since the s and the r processes require neutron densities that are more than ten orders of magnitude apart, and hence are thought to occur in very different stellar sites. We investigate whether the abundance patterns of CEMP-s/r stars can arise from the nucleosynthesis of the intermediate neutron-capture process (the i process), which is characterised by neutron densities between those of the s and the r processes. Using nuclear network calculations, we study neutron capture nucleosynthesis at different constant neutron densities n ranging from 10 7 to 10 15 cm −3 . Neutron densities on the highest side of this range result in abundance patterns that show an increased production of heavy s-and r-process elements but similar levels of the light s-process elements. With our i-process model, we are able to reproduce the abundance patterns of 20 CEMP-s/r stars that could not be explained by s-process nucleosynthesis.KEYWORDS: nucleosynthesis, stars: population II, stars: carbon MethodThe nucleosynthesis tools that we use are NucNet Tools, a set of C/C++ codes developed by Bradley S. Meyer [1]. In this study, the codes are used to follow the nuclear processing of a single zone with given initial composition under conditions of fixed temperature, density and neutron density. The nuclear network used for this project contains the 5442 isotopes and 45831 reactions from the JINA Reaclib V0.5 database [2]. In more recent releases, neutron-capture reaction rates from KADoNiS v0.2 [3] are included and refitted to eliminate blow-ups at low temperatures and to match the theory at higher temperatures (JINA Reaclib label kd02). However, in some cases the fits underpredict the rates in the temperature regime relevant for the conditions in an AGB intershell region, with deviations up to two orders of magnitude, for example, in the case of 151 Eu(n,γ) 152 Eu. Such a large underprediction of the reaction rate introduces artificial bottlenecks on the neutron capture path. Because of this, we use the previous version of the the refitted rates (JINA Reaclib label ka02).The physical input conditions are adapted from the density and temperature profiles of the intershell region that [4] found for a low-metallicity AGB star. In particular, we present here the test case with T = 1.5 × 10 8 K and ρ = 1600 g cm −3 . To model the nucleosynthesis in the intershell region, the composition of the input zone is adapted from the intershell composition of [5]. In particular, we use the abundances of 320 isotopes from an AGB star model with metallicity Z = 10 −4 and initial mass 1

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The Jina Reaclib Database: Its Recent Updates and Impact on Type-I X-Ray Bursts

Cited by 965 publications

References 157 publications

Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313−6708 and the most iron-poor stars

Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313−6708 and the most iron-poor stars

Lithium and boron burning S(E)-factor measurements at astrophysical energies via the Trojan Horse Method

Carbon-Enhanced Metal-Poor Stars and the Need for an Intermediate Neutron Capture Process

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