Galactic r-process abundance feature shaped by radial migration

Abstract

Growing interests in the chemical feature of r-process elements among nearby disk stars represented by the [Eu/Fe] vs. [Fe/H] diagram have sprouted since it can assess the origin of r-process elements through the comparison with theoretical models, including a test as to if neutron star mergers can be the major site of r-process nucleosynthesis. On the other hand, recent studies reveal that local chemistry is strongly coupled with the dynamics of Galactic disk, which predicts that stars radially move on the disk where the observed elemental feature is different at various Galactocentric distances. Here, we show that radial migration of stars across the Galactic disk plays a crucial role in shaping the r-process abundance feature in the solar vicinity. In this proposed scenario, we highlight the importance of migration from the outer disk where [r-process/Fe] of some old stars is predicted to be enhanced to the level beyond the expectation from the observed Galactic Fe and Eu radial gradient, which results in a large span of [r-process/Fe] among nearby disk stars. The variation in the [r-process/Fe] ratio seen across the Galactic disk as well as in dwarf galaxies may be an outcome of different stellar initial mass functions which change the occurrence frequency between supernovae leaving behind neutron stars and ones ending with black holes. Here we propose that enhancement in [Eu/Fe] is attributed to the initial mass function lacking high-mass stars such as > 25 solar masses in the scheme for which neutron star mergers are a major source of r-process elements.

11 pages including 6 figures, accepted for publication in ApJ

References in corpus (95)

• The merger that led to the formation of the Milky Way's inner stellar halo and thick disk
• Radial Mixing in Galactic Discs
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. II. UV, Optical, and Near-IR Light Curves and Comparison to Kilonova Models
• Spectroscopic identification of r-process nucleosynthesis in a double neutron star merger
• Elemental Abundance Survey of The Galactic Thick Disk
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• The Chemical Compositions of Galactic Disk F and G Dwarfs
• Chemical evolution with radial mixing
• Abundance Gradients and the Formation of the Milky Way
• Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
• Effect of a High Opacity on the Light Curves of Radioactively Powered Transients from Compact Object Mergers
• Mass Limits For Black Hole Formation
• Comparison of H-alpha and UV Star Formation Rates in the Local Volume: Systematic Discrepancies for Dwarf Galaxies
• Galactic-Field IMFs of Massive Stars
• A dynamically young and perturbed Milky Way disk
• Riding the Spiral Waves: Implications of Stellar Migration for the Properties of Galactic Disks
• The Stellar Abundances for Galactic Archeology (SAGA) Database - Compilation of the Characteristics of Known Extremely Metal-Poor Stars
• Collapsars as a major source of r-process elements
• Physical properties of molecular clouds for the entire Milky Way disk
• A New Mechanism for Radial Migration in Galactic Disks: Spiral-Bar Resonance Overlap
• Origin and structure of the Galactic disc(s)
• Neutron star mergers versus core-collapse supernovae as dominant r-process sites in the early Galaxy
• Neutron Star Mergers and Nucleosynthesis of Heavy Elements
• Supernova Nucleosynthesis in Population III 13 -- 50 $M_{\odot }$ Stars and Abundance Patterns of Extremely Metal-Poor Stars
• Footprints of the Sagittarius dwarf galaxy in the $Gaia$ data set
• The Milky Way has no thick disk
• Evidence for a Non-Uniform Initial Mass Function in the Local Universe
• Delay Time Distribution Measurement of Type Ia Supernovae by the Subaru/XMM-Newton Deep Survey and Implications for the Progenitor
• The Genesis of the Milky Way's Thick Disk via Stellar Migration
• Chemodynamical evolution of the Milky Way disk II: Variations with Galactic radius and height above the disk plane
• Neutron Star Mergers Might not be the Only Source of r-Process Elements in the Milky Way
• A Simple Approach to the Supernova Progenitor-Explosion Connection
• Vertical density waves in the Milky Way disc induced by the Sagittarius Dwarf Galaxy
• A high resolution VLT/FLAMES study of individual stars in the centre of the Fornax dwarf spheroidal galaxy
• The GALAH survey and Gaia DR2: dissecting the stellar disc's phase space by age, action, chemistry and location
• Tracing chemical evolution over the extent of the Milky Way's Disk with APOGEE Red Clump Stars
• Oxygen Abundances in Nearby Stars. Clues to the formation and evolution of the Galactic disk
• The Variation of Integrated Star IMFs among Galaxies
• On the fine structure of the Cepheid metallicity gradient in the Galactic thin disk
• Alpha element abundances and gradients in the Milky Way bulge from FLAMES-GIRAFFE spectra of 650 K giants
• Galactic Archaeology with asteroseismic ages: evidence for delayed gas infall in the formation of the Milky Way disc
• Chemistry of the Sagittarius Dwarf Galaxy: a Top-Light IMF, Outflows and the R-Process
• A Density Independent Formulation of Smoothed Particle Hydrodynamics
• Europium production: neutron star mergers versus core-collapse supernovae
• Dynamics of Non-Steady Spiral Arms in Disk Galaxies
• Neutron Star Mergers as sites of r-process Nucleosynthesis and Short Gamma-Ray Bursts
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. IV. A New Sample of Open Clusters
• Toward first-principle simulations of galaxy formation: I. How should we choose star formation criteria in high-resolution simulations of disk galaxies?
• Signatures of radial migration in barred galaxies: Azimuthal variations in the metallicity distribution of old stars
• Radial mixing in the outer Milky Way disk caused by an orbiting satellite
• The origin and evolution of r- and s-process elements in the Milky Way stellar disk
• Fossil Imprints of the First Generation Supernova Ejecta in Extremely Metal-Deficient Stars
• Light, Alpha, and Fe-Peak Element Abundances in the Galactic Bulge
• Origin of chemically distinct discs in the Auriga cosmological simulations
• Radial Mixing in Galactic Disks: The Effects of Disk Structure and Satellite Bombardment
• Abundance gradients in the Milky Way for alpha elements, Iron peak elements, Barium, Lanthanum and Europium
• The role of neutron star mergers in the chemical evolution of the Galactic halo
• Warp, Waves, and Wrinkles in the Milky Way
• Radial Distribution of Stellar Motions in Gaia DR2
• Diverging UV and Halpha fluxes of star forming galaxies predicted by the IGIMF theory
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VIII. A Comparison to Cosmological Short-duration Gamma-ray Bursts
• Enrichment of r-process elements in dwarf spheroidal galaxies in chemo-dynamical evolution model
• Cepheid Abundances: Multiphase Results and Spatial Gradients
• VLT/FLAMES spectroscopy of red giant branch stars in the Fornax dwarf spheroidal galaxy
• The AMBRE project: The thick thin disk and thin thick disk of the Milky Way
• Understanding inverse metallicity gradients in galactic discs as a consequence of inside-out formation
• Constraints on the Formation of the Galactic Bulge from Na, Al, and Heavy Element Abundances in Plaut's Field
• Clustered star formation as a natural explanation of the Halpha cutoff in disc galaxies
• PUSHing Core-Collapse Supernovae to Explosions in Spherical Symmetry II: Explodability and Global Properties
• Excitation of coupled stellar motions in the Galactic Disk by orbiting satellites
• Impact of radial migration on stellar and gas radial metallicity distribution
• The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis. II. Early chemical enrichment
• On the alpha-element gradients of the Galactic thin disk using Cepheids
• Enrichment history of r-process elements shaped by a merger of neutron star pairs
• Accretion, radial flows and abundance gradients in spiral galaxies
• Chemical evolution library for galaxy formation simulation
• High-resolution abundance analysis of red giants in the globular cluster NGC 6522
• Short-term dynamical evolution of grand-design spirals in barred galaxies
• The Delay Time Distribution of Type Ia Supernovae and the Single Degenerate Model
• A universal route for the formation of massive star clusters in giant molecular clouds
• The Populations of Carina. II. Chemical Enrichment
• Two-Component Galactic Bulge Probed with Renewed Galactic Chemical Evolution Model
• The chemical evolution of r-process elements from neutron star mergers: the role of a 2-phase interstellar medium
• Early chemo-dynamical evolution of dwarf galaxies deduced from enrichment of r-process elements
• On the neutron-capture elements across the Galactic thin disk using Cepheids
• The delayed time distribution of massive double compact star mergers
• The AMBRE Project: r-process elements in the Milky Way thin and thick discs
• New Neutron-Capture Measurements in 23 Open Clusters. I. The R-Process
• Origin of chemical and dynamical properties of the Galactic thick disk
• Migration and kinematics in growing disc galaxies with thin and thick discs
• The thick disk rotation-metallicity correlation as a fossil of an "inverse chemical gradient" in the early Galaxy
• Chemical Signature Indicating A Lack of Massive Stars in Dwarf Galaxies
• Looking for imprints of the first stellar generations in metal-poor bulge field stars
• Chemical evolution of 244Pu in the solar vicinity and its implication for the properties of r-process production
• Metallicity Gradient of the Thick Disc Progenitor at High Redshift

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• Modelling the chemical evolution of Zr, La, Ce and Eu in the Galactic discs and bulge
• Neutron Star Mergers as the Main Source of R-process: Natal Kicks And Inside-Out Evolution to The Rescue
• Evidence for r-process delay in very metal-poor stars
• Identification of Absorption Lines of Heavy Metals in the Wavelength Range 0.97--1.32 Micron
• The impact of turbulent mixing on the galactic r-process enrichment by binary neutron star mergers
• Metallicity-Suppressed Collapsars Cannot be the Dominant r-Process Source in the Milky Way
• Two Sites of r-Process Production Assessed on the Basis of the Age-tagged Abundances of Solar Twins