The s-process in the Galactic halo: the fifth signature of spinstars in the early Universe?

Abstract

Very old halo stars were previously found to show at least four different abundance 'anomalies', which models of fast rotating massive stars (spinstars) can successfully account for: rise of N/O and C/O, low 12C/13C and a primary-like evolution of Be and B. Here we show the impact of these same stars in the enrichment of Sr and Ba in the early Universe. We study if the s-process production of fast rotating massive stars can offer an explanation for the observed spread in [Sr/Ba] ratio in halo stars with metallicity [Fe/H]< -2.5. By means of a chemical inhomogeneous model we compute the enrichment of Sr and Ba by massive stars in the Galactic halo. Our model takes into account, for the first time, the contribution of spinstars. Our model (combining an r-process contribution with a s-process from fast rotating massive stars) is able to reproduce for the first time the observed scatter in the [Sr/Ba] ratio at [Fe/H]< -2.5. Toward higher metallicities, the stochasticity of the star formation fades away due to the increasing number of exploding and enriching stars, and as a consequence the predicted scatter decreases. Our scenario is again based on the existence of spinstars in the early Universe. Very old halo stars were previously found to show at least four other abundance 'anomalies', which rotating models of massive stars can successfully account for. Our results provide a 5th independent signature of the existence of fast rotating massive stars: an early enrichment of the Universe in s-process elements.

14 pages, 7 figures, minor changes to match published version in A&A

References in corpus (35)

• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• On the astrophysical robustness of neutron star merger r-process
• Nucleosynthetic signatures of the first stars
• Magnetorotationally driven Supernovae as the origin of early galaxy $r$-process elements?
• First stars VI - Abundances of C, N, O, Li, and mixing in extremely metal-poor giants. Galactic evolution of the light elements
• An extremely primitive halo star
• First Stars VIII -- Enrichment of the neutron-capture elements in the early Galaxy
• Near-UV Observations of HD221170: New Insights into the Nature of r-Process-Rich Stars
• Binary star progenitors of long gamma-ray bursts
• Nucleosynthesis-relevant conditions in neutrino-driven supernova outflows. I. Spherically symmetric hydrodynamic simulations
• The Most Metal-Poor Stars. IV. The Two Populations With [Fe/H] < -3.0
• A strong case for fast stellar rotation at very low metallicities
• Production of Light Element Primary Process nuclei in neutrino-driven winds
• The Frequency of Carbon-Enhanced Metal-Poor Stars in the Galaxy from the HERES sample
• The s process in massive stars at low metallicity. Effect of primary N14 from fast rotating stars
• The stellar content of the Hamburg/ESO survey. IV. Selection of candidate metal-poor stars
• Nucleosynthesis in the Early Galaxy
• First stars IX -Mixing in extremely metal-poor giants. Variation of the 12C/13C, [Na/Mg] and [Al/Mg] ratios
• HE 1327-2326, an unevolved star with [Fe/H]<-5.0. II. New 3D-1D corrected abundances from a VLT/UVES spectrum
• New Extremely Metal-Poor Stars in the Galactic Halo
• Stellar Archaeology -- Exploring the Universe with Metal-Poor Stars
• The Most Metal-Poor Stars. III. The Metallicity Distribution Function and CEMP Fraction
• CS 30322-023: an ultra metal-poor TP-AGB star?
• Nucleosynthesis Modes in the High-Entropy-Wind of Type II Supernovae: Comparison of Calculations with Halo-Star Observations
• A new imprint of fast rotators: low 12C/13C ratios in extremely metal-poor halo stars
• An inhomogeneous model for the Galactic halo: a possible explanation for the spread observed in s- and r-process elements
• Are There Any Stars Lacking Neutron-Capture Elements? Evidence from Strontium and Barium
• Rotation and Internal Structure of Population III Protostars
• Carbon and Strontium Abundances of Metal-Poor Stars
• Dependence of S-Process Nucleosynthesis in Massive Stars on Triple-Alpha and 12C(a,g)16O Reaction Rate Uncertainties
• The Hobby-Eberly Telescope "Chemical Abundances of Stars in the Halo" (CASH) Project. I. The Lithium-, s-, and r-Enhanced Metal-Poor Giant HKII 17435-00532
• Nucleosynthesis in neutron-rich ejecta from quark-novae
• Mass-loss predictions for evolved very metal-poor massive stars
• SPINSTARS at low metallicities
• First Stars IV: Summary Talk

Cited by in corpus (96)

• Chemical evolution with rotating massive star yields: I. The solar neighbourhood and the s-process elements
• $s$-process production in rotating massive stars at solar and low metallicities
• Chemodynamical history of the Galactic Bulge
• Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program II: Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu
• Binarity in Carbon-Enhanced Metal-Poor stars
• Europium production: neutron star mergers versus core-collapse supernovae
• Massive double compact object mergers: gravitational wave sources and r-process-element production sites
• r-Process Nucleosynthesis: Connecting Rare-Isotope Beam Facilities with the Cosmos
• The History of R-Process Enrichment in the Milky Way
• The R-Process Alliance: First Release from the Northern Search for r-Process Enhanced Metal-Poor Stars in the Galactic Halo
• The role of neutron star mergers in the chemical evolution of the Galactic halo
• The EMBLA Survey -- Metal-poor stars in the Galactic bulge
• Chemical Abundances in the Ultra-Faint Dwarf Galaxies Grus I and Triangulum II: Neutron-Capture Elements as a Defining Feature of the Faintest Dwarfs
• Exploring the Origin of Lithium, Carbon, Strontium and Barium with four new Ultra Metal-Poor Stars
• Explaining the Ba, Y, Sr, and Eu abundance scatter in metal-poor halo stars: constraints to the r-process
• Neutron-Capture Nucleosynthesis in the First Stars
• Non standard s-process in massive rotating stars. Yields of $10-150$ $M_{\odot }$ models at $Z=10^{-3}$
• Elevated r-process enrichment in Gaia Sausage and Sequoia
• The first stars: CEMP--no stars and signatures of spinstars
• The early days of the Sculptor dwarf spheroidal galaxy
• Nine New Metal-Poor Stars on the Subgiant and Red Horizontal Branches with High Levels of r-process Enhancement
• High-resolution abundance analysis of red giants in the globular cluster NGC 6522
• Metal-Poor Stars Observed with the Magellan Telescope II. Discovery of Four Stars with [Fe/H] < -3.5
• The s Process and Beyond
• Galactic Chemical Evolution: the Impact of the 13C-pocket Structure on the s-process Distribution
• Abundances of carbon-enhanced metal-poor stars as constraints on their formation
• High-resolution spectroscopic studies of ultra metal-poor stars found in LAMOST survey
• Uncertainties in s-process nucleosynthesis in massive stars determined by Monte Carlo variations
• Are some CEMP-s stars the daughters of spinstars?
• The New Model of Chemical Evolution of r-process Elements Based on The Hierarchical Galaxy Formation I: Ba and Eu
• Probing astrophysically important states in ${}^{26}$Mg nucleus to study neutron sources for the $s$-Process
• Abundance patterns of the light neutron-capture elements in very and extremely metal-poor stars
• Enrichment of Zinc in galactic chemodynamical evolution models
• Stellar abundances and presolar grains trace the nucleosynthetic origin of molybdenum and ruthenium
• An inefficient dwarf: Chemical abundances and the evolution of the Ursa Minor dwarf spheroidal galaxy
• Origin of Cosmic Chemical Abundances
• High-resolution abundance analysis of red giants in the metal-poor bulge globular cluster HP~1
• Origin of the CEMP-no Group Morphology in the Milky Way
• The R-Process Alliance: The Peculiar Chemical Abundance Pattern of RAVE J183013.5-455510
• Evolution of neutron capture elements in dwarf galaxies
• The Impact of Black Hole Formation on Population Averaged Supernova Yields
• Constraints on stellar rotation from the evolution of Sr and Ba in the Galactic halo
• The R-Process Alliance: Abundance Universality among Some Elements at and between the First and Second R-Process Peaks
• Stellar winds and metal enrichment from fast-rotating Population III stars
• Tracing Pop III supernovae with extreme energies through the Sculptor dwarf spheroidal galaxy
• Modelling the chemical evolution of Zr, La, Ce and Eu in the Galactic discs and bulge
• Correlations of r-Process Elements in Very Metal-Poor Stars as Clues to their Nucleosynthesis Sites
• Diversity of Abundance Patterns of Light Neutron-capture Elements in Very-metal-poor Stars
• Are ancient dwarf satellites the building blocks of the Galactic halo?
• Rapidly rotating Population III stellar models as a source of primary nitrogen
• The Origin of the Heaviest Metals in Most Ultra-Faint Dwarf Galaxies
• Trans-iron Ge, As, Se, and heavier elements in the dwarf metal-poor stars, HD~19445, HD~84937, HD~94028, HD~140283, and HD~160617
• Enrichment of Strontium in Dwarf Galaxies
• The R-Process Alliance: Discovery of a low-alpha, r-Process-Enhanced Metal-Poor Star in the Galactic Halo
• Looking for imprints of the first stellar generations in metal-poor bulge field stars
• A spectroscopic binary in the Hercules dwarf spheroidal galaxy
• Manganese spread in Ursa Minor as a proof of sub-classes of type Ia supernovae
• The cerium content of the Milky Way as revealed by Gaia DR3 GSP-Spec abundances
• Re-evaluation of the ${}^{16}$O($n$,$\gamma$)${}^{17}$O cross section at astrophysical energies and its role as neutron poison in the $s$ process
• 2D chemical evolution models II. Effects of multiple spiral arm patterns on O, Eu, Fe and Ba abundance gradients
• A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in omega Centauri
• The universality of the rapid neutron-capture process revealed by a possible disrupted dwarf galaxy star
• Nucleosynthetic yields of Z=$10^{-5}$ intermediate-mass stars
• Inhomogeneous Galactic Chemical Evolution: Modelling Ultra-Faint Dwarf Galaxies of the Large Magellanic Cloud
• Reanalysis of neutron-capture elements in the benchmark r-rich star CS 31082-001
• Time evolution of Ce as traced by APOGEE using giant stars observed with the Kepler, TESS and K2 missions
• The impact of ${}^{17}$O$+\alpha$ reaction rate uncertainties on the s-process in rotating massive stars
• Explaining the ${}^{12}\text{C}{/}^{13}\text{C}$ ratio in the Galactic halo: the contribution from shell mergers in primordial massive stars
• Nucleosynthesis signatures of neutrino-driven winds from proto-neutron stars: a perspective from chemical evolution models
• The formation of the Milky Way halo and its dwarf satellites: a NLTE-1D abundance analysis. IV. Segue 1, Triangulum II, and Coma Berenices UFDs
• High resolution study of the abundance pattern of the heavy elements in very metal-poor field stars
• Observational nuclear astrophysics: neutron-capture element abundances in old, metal-poor stars
• Chemical Evolution of R-process Elements in Stars (CERES). III. Chemical abundances of neutron capture elements from Ba to Eu
• Neutrino-driven Core-collapse Supernova Yields in Galactic Chemical Evolution
• A direct measurement of the 17O(a,g)21Ne reaction in inverse kinematics and its impact on heavy element production
• The s process in massive stars, a benchmark for neutron capture reaction rates
• Does the chemical signature of TYC 8442-1036-1 originate from a rotating massive star that died in a faint explosion?
• Unlocking the mystery of Sr synthesis in the early Galaxy through analysis of barium isotopes in very metal-poor stars
• The oldest stars with low neutron-capture element abundances and origins in ancient dwarf galaxies
• Neutron-Capture Element Signatures in Globular Clusters: Insights from the Gaia-ESO Survey
• Abundances of disk and bulge giants from high-resolution optical spectra V. Molybdenum -- the p-process element
• The neutron-capture and alpha-elements abundance ratios scatter in old stellar populations. Cosmological simulations of the stellar halo
• The oldest stars of the bulge: new information on the ancient Galaxy
• Recent Advances in Understanding R-Process Nucleosynthesis in Metal-Poor Stars and Stellar Systems
• Dependence of the Sr-to-Ba and Sr-to-Eu Ratio on the Nuclear Equation of State in Metal Poor Halo Stars
• Modelling the chemical evolution of the Milky Way
• Neutron-capture elements in a sample of field metal-poor N-rich dwarfs
• The impact of rare events on the chemical enrichment in dwarf galaxies
• Massive stars: stellar models and stellar yields, impact on Galactic Archaeology
• Footprints of the weak s-process in the carbon-enhanced metal-poor star ET0097
• Photo-chemo-dynamical analysis and the origin of the bulge globular cluster Palomar 6
• Gaia-Sausage-Enceladus: Lithium evolution from early red-giant-branch and main-sequence stars
• The COMBS Survey -- III. The Chemodynamical Origins of Metal-Poor Bulge Stars
• UVES analysis of red giants in the bulge globular cluster NGC 6522
• Barium lines in high-quality spectra of two metal-poor giants in the Galactic halo
• Detailed Abundance Determination of Metal-Poor Stars with X-Shooter I. Unusual Chemistry in Halo Stars