The effects of rotation on the s-process nucleosynthesys in Asymptotic Giant Branch stars

Abstract

In this paper we analyze the effects induced by rotation on low mass Asymptotic Giant Branch stars. We compute two sets of models, M=2.0 Msun at [Fe/H]=0 and M=1.5 Msun at [Fe/H]=-1.7, respectively, by adopting Main Sequence rotation velocities in the range 0 - 120 km/s. At high metallicity, we find that the Goldreich-Schubert-Fricke instability, active at the interface between the convective envelope and the rapid rotating core, contaminates the 13C-pocket (the major neutron source) with 14N (the major neutron poison), thus reducing the neutron flux available for the synthesis of heavy elements. As a consequence, the yields of heavy-s elements (Ba, La, Nd, Sm) and, to a less extent, those of light-s elements (Sr, Y, Zr) decrease with increasing rotation velocities up to 60 km/s. However, for larger initial rotation velocities, the production of light-s and, to a less extent, that of heavy-s begins again to increase, due to mixing induced by meridional circulations. At low metallicity, the effects of meridional circulations are important even at rather low rotation velocity. The combined effect of Goldreich-Schubert-Fricke instability and meridional circulations determines an increase of light-s and, to a less extent, heavy-s elements, while lead is strongly reduced. For both metallicities, the rotation-induced instabilities active during the interpulse phase reduce the neutrons-to-seeds ratio, so that the spectroscopic indexes [hs/ls] and [Pb/hs] decrease by increasing the initial rotation velocity. Our analysis suggests that rotation could explain the spread in the s-process indexes, as observed in s-process enriched stars at different metallicities.

41 pages, 11 figures, accepted for the publication on ApJ

References in corpus (7)

• Pre-Supernova Evolution of Massive Single and Binary Stars
• The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
• White dwarf spins from low mass stellar evolution models
• A Revised Prescription for the Tayler-Spruit Dynamo: Magnetic Angular Momentum Transport in Stars
• A Method to Derive the Absolute Composition of the Sun, the Solar System and the Stars
• Pre-Explosive Observational Properties of Type Ia Supernovae
• Mixing of CNO-cycled matter in massive stars

Cited by in corpus (81)

• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• Revisiting the bound on axion-photon coupling from Globular Clusters
• Chemical evolution with rotating massive star yields: I. The solar neighbourhood and the s-process elements
• Evolution, nucleosynthesis and yields of AGB stars at different metallicities (III): intermediate mass models, revised low mass models and the ph-FRUITY interface
• Stellar yields from metal-rich asymptotic giant branch models
• NuGrid stellar data set I. Stellar yields from H to Bi for stars with metallicities Z = 0.02 and Z = 0.01
• Cool WISPs for stellar cooling excesses
• Binarity in Carbon-Enhanced Metal-Poor stars
• Evolution and nucleosynthesis of asymptotic giant branch stellar models of low metallicity
• Nitrogen enhancements 440 Myr after the Big Bang: super-solar N/O, a tidal disruption event or a dense stellar cluster in GN-z11?
• Helium enrichment and Carbon-star Production in Metal-rich Populations
• Heavy-element yields and abundances of Asymptotic Giant Branch models with a Small Magellanic Cloud metallicity
• The Branchings of the Main s-process: Their Sensitivity to alpha-induced Reactions on 13C and 22Ne and to the Uncertainties of the Nuclear Network
• H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis
• Barium Isotopic Composition of Mainstream Silicon Carbides from Murchison: Constraints for s-Process Nucleosynthesis in AGB Stars
• Application of a Theory and Simulation based Convective Boundary Mixing model for AGB Star Evolution and Nucleosynthesis
• Planetary Nebulae: Sources of Enlightenment
• Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison
• On the need of the Light Elements Primary Process (LEPP)
• Magnetic-buoyancy Induced Mixing in AGB Stars: Presolar SiC Grains
• The RGB tip of galactic globular clusters and the revision of the bound of the axion-electron coupling
• The s Process and Beyond
• MHD and deep mixing in evolved stars. 1. 2D and 3D analytical models for the AGB
• NuGrid stellar data set - III. Updated low-mass AGB models and s-process nucleosynthesis with metallicities Z=0.01, Z=0.02 and Z=0.03
• Heavy elements in Globular Clusters: the role of AGB stars
• The importance of the 13C(alpha,n)16O reaction in Asymptotic Giant Branch stars
• Abundances of carbon-enhanced metal-poor stars as constraints on their formation
• Galactic Chemical Evolution: the Impact of the 13C-pocket Structure on the s-process Distribution
• The impact of updated Zr neutron-capture cross sections and new asymptotic giant branch models on our understanding of the s process and the origin of stardust
• The s process in AGB stars as constrained by a large sample of Barium stars
• Constraints of the physics of low-mass AGB stars from CH and CEMP stars
• s-Processing in AGB Stars Revisited. I. Does the Main Component Constrain the Neutron Source in the 13C-Pocket?
• The 13C-Pocket Structure in AGB Models: Constraints from Zirconium Isotope Abundances in Single Mainstream SiC Grains
• s-Processing in AGB Stars Revisited. III. Neutron captures from MHD mixing at different metallicities and observational constraints
• Do meteoritic silicon carbide grains originate from asymptotic giant branch stars of super-solar metallicity?
• Observational and theoretical constraints on the formation and early evolution of the first dust grains in galaxies at 5 < z < 10
• Post-AGB stars in the Magellanic Clouds and neutron-capture processes in AGB stars
• Concurrent application of ANC and THM to assess the ${}^{13}\mathrm{C}(\alpha ,n{)}^{16}\mathrm{O}$ absolute cross section at astrophysical energies and possible consequences for neutron production in low-mass AGB stars
• Magnetic-buoyancy-induced mixing in AGB Stars: fluorine nucleosynthesis at different metallicities
• Nucleosynthesis in helium-enriched asymptotic giant branch models: Implications for Heavy Element Enrichment in Omega Centauri
• On the neutron-capture elements across the Galactic thin disk using Cepheids
• The puzzle of the CNO isotope ratios in AGB carbon stars
• The Abundances of Light Neutron-Capture Elements in Planetary Nebulae III. The Impact of New Atomic Data on Nebular Selenium and Krypton Abundance Determinations
• Barium stars as tracers of s-process nucleosynthesis in AGB stars I. 28 stars with independently derived AGB mass
• Origin of large meteoritic SiC stardust grains in metal-rich AGB stars
• New constraints on the major neutron source in low-mass AGB stars
• Rotation of the asymptotic giant branch star R Doradus
• Exploring the s-process history in the Galactic disk: Cerium abundances and gradients in Open Clusters from the OCCAM/APOGEE sample
• The lead discrepancy in intrinsically s-process enriched post-AGB stars in the Magellanic Clouds
• The impact of the revised ${}^{17}$O$(p,\alpha {)}^{14}$N reaction rate on ${}^{17}$O stellar abundances and yields
• Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements
• Evolution and nucleosynthesis of helium-rich asymptotic giant branch models
• On the mass and metallicity distribution of parent AGB stars of presolar SiC
• Characterizing the companion AGBs using surface chemical composition of barium stars
• The initial mass-final luminosity relation of type II supernova progenitors. Hints of new physics?
• The s process in rotating low-mass AGB stars. Nucleosynthesis calculations in models matching asteroseismic constraints
• The s-Process Enrichment of the Globular Clusters M4 and M22
• Barium stars as tracers of s-process nucleosynthesis in AGB stars II. Using machine learning techniques on 169 stars
• The Goldreich-Schubert-Fricke instability in stellar radiative zones
• The carbon star mystery: forty years later
• A high-precision abundance analysis of the nuclear benchmark star HD 20
• NGC 1261: an $r$-process enhanced globular cluster from the Gaia-Enceladus event
• Stellar cooling anomalies and variant axion models
• A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in omega Centauri
• IR characteristic emission and dust properties of star-forming galaxies at 4.5 $<$ z $<$ 6.2
• Nucleosynthesis signatures of neutrino-driven winds from proto-neutron stars: a perspective from chemical evolution models
• The FRUITY database on AGB stars: past, present and future
• The peculiar abundances of HE 1005-1439. A carbon-enhanced extremely metal-poor star contaminated with products of both s-and i-process nucleosynthesis
• Slow Neutron-Capture Process: Low-mass AGB stars and presolar silicon carbide grains
• Barium stars as tracers of s-process nucleosynthesis in AGB stars III. Systematic deviations from the AGB models
• Presolar Silicon Carbide Grains of Types Y and Z: Their Strontium and Barium Isotopic Compositions and Stellar Origins
• Presolar grains
• On the mass of supernova progenitors: the role of the ${}^{12}$C${+}^{12}$C reaction
• The impact of third dredge-up on the mass loss of Mira variables
• s-process Enriched Post-AGB Star J003643.94-723722.1 in the SMC with an Extreme C/O Ratio and the First Precise Detection of Lead
• First models of s process in AGB stars of solar metallicity for the stellar evolutionary code ATON with a novel stable explicit numerical solver
• [Rb/Zr] ratio in Ba stars as diagnostics of the companion AGB stellar mass
• Production of n-rich nuclei in red giant stars
• CEMP-s and CEMP-s/r stars: last update
• Dust Production around Carbon-Rich Stars: The Role of Metallicity
• The ${}^{13}C$-pockets in AGB Stars and Their Fingerprints in Mainstream SiC Grains