Current Status of r-Process Nucleosynthesis

Abstract

The rapid neutron capture process (r process) is believed to be responsible for about half of the production of the elements heavier than iron and contributes to abundances of some lighter nuclides as well. A universal pattern of r-process element abundances is observed in some metal-poor stars of the Galactic halo. This suggests that a well-regulated combination of astrophysical conditions and nuclear physics conspires to produce such a universal abundance pattern. The search for the astrophysical site for r-process nucleosynthesis has stimulated interdisciplinary research for more than six decades. There is currently much enthusiasm surrounding evidence for r-process nucleosynthesis in binary neutron star mergers in the multi-wavelength follow-up observations of kilonova/gravitational-wave GRB170807A/GW170817. Nevertheless, there remain questions as to the contribution over the history of the Galaxy to the current solar-system r-process abundances from other sites such as neutrino-driven winds or magnetohydrodynamical ejection of material from core-collapse supernovae. In this review we highlight some current issues surrounding the nuclear physics input, astronomical observations, galactic chemical evolution, and theoretical simulations of r-process astrophysical environments with the goal of outlining a path toward resolving the remaining mysteries of the r process.

References in corpus (63)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• Multi-messenger Observations of a Binary Neutron Star Merger
• An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
• Origin of the heavy elements in binary neutron-star mergers from a gravitational wave event
• 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
• INTEGRAL Detection of the First Prompt Gamma-Ray Signal Coincident with the Gravitational Wave Event GW170817
• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• The X-ray counterpart to the gravitational wave event GW 170817
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• The Combined Ultraviolet, Optical, and Near-Infrared Light Curves of the Kilonova Associated with the Binary Neutron Star Merger GW170817: Unified Data Set, Analytic Models, and Physical Implications
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XII: Stiffness and stability of neutron-star matter
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. IV. Detection of Near-infrared Signatures of r-process Nucleosynthesis with Gemini-South
• Magnetorotationally driven Supernovae as the origin of early galaxy $r$-process elements?
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. III. Optical and UV Spectra of a Blue Kilonova From Fast Polar Ejecta
• Neutron Star Mergers and Nucleosynthesis of Heavy Elements
• Galactic Chemical Evolution and solar s-process abundances: dependence on the 13C-pocket structure
• Asymmetries in core-collapse supernovae from maps of radioactive ${}^{44}$Ti in CassiopeiaA
• First Penning-trap mass measurement in the millisecond half-life range: the exotic halo nucleus 11Li
• The intermediate r-process in core-collapse supernovae driven by the magneto-rotational instability
• Production of the entire range of r-process nuclides by black hole accretion disc outflows from neutron star mergers
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. IX: Constraint of pairing force to ${}^1{S}_0$ neutron-matter gap
• Special Relativistic Simulations of Magnetically-dominated Jets in Collapsing Massive Stars
• Evolution of the N=50 shell gap energy towards ${}^{78}$Ni
• Novel technique for constraining r-process (n,$\gamma$) reaction rates
• Direct mass measurements of 19B, 22C, 29F, 31Ne, 34Na and other light exotic nuclei
• Disk-Jet Coupling in Black Hole Accretion Systems I: General Relativistic Magnetohydrodynamical Models
• "Meissner effect" and Blandford-Znajek mechanism in conductive black hole magnetospheres
• Early 56Ni decay γ-rays from SN2014J suggest an unusual explosion
• Beta-decay half-lives and beta-delayed neutron emission probabilities of nuclei in the region below A=110, relevant for the r-process
• 3D Relativistic Magnetohydrodynamic Simulations of Magnetized Spine-Sheath Relativistic Jets
• i-process nucleosynthesis and mass retention efficiency in He-shell flash evolution of rapidly accreting white dwarfs
• A Neutron Star Binary Merger Model for GW170817/GRB170817a/SSS17a
• Stellar explosions powered by the Blandford-Znajek mechanism
• Axisymmetric simulations of magnetorotational core collapse: Approximate inclusion of general relativistic effects
• Improved Laboratory Transition Probabilities for Er II and Applications to the Erbium Abundances of the Sun and Five r-Process Rich, Metal-Poor Stars
• Half-lives and branchings for β-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process
• SN2014J gamma-rays from the 56Ni decay chain
• Numerical Study on GRB-Jet Formation in Collapsars
• Nucleosynthesis in Magnetically Driven Jets from Collapsars
• Natal Kicks and Time Delays in Merging Neutron Star Binaries - Implications for r-process nucleosynthesis in Ultra Faint Dwarfs and in the Milky Way
• Mass measurements beyond the major r-process waiting point 80Zn
• Enrichment history of r-process elements shaped by a merger of neutron star pairs
• Heavy element nucleosynthesis in a collapsar
• Mass measurements near the $r$-process path using the Canadian Penning Trap mass spectrometer
• Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path
• New measurement of neutron capture resonances of 209Bi
• Magnetohydrodynamic Simulations of A Rotating Massive Star Collapsing to A Black Hole
• Contribution of Neutron Star Mergers to the R-process Chemical Evolution in the Hierarchical Galaxy Formation
• 26Al kinematics: superbubbles following the spiral arms? Constraints from the statistics of star clusters and HI supershells
• Modelling the Type Ic SN 2004aw: a Moderately Energetic Explosion of a Massive C+O Star without a GRB
• Long-Term Evolution of Slowly Rotating Collapsar in Special Relativistic Magnetohydrodynamics
• Determining neutron-capture cross sections via the surrogate reaction technique
• Enrichment in r-process elements from multiple distinct events in the early Draco dwarf spheroidal galaxy
• Detailed illustration of accuracy of presently used nuclear-mass models
• Explosive Nucleosynthesis in Magnetohydrodynamical Jets from Collapsars II. Heavy-Element Nucleosynthesis of s, r, p-Processes
• Diversity of Abundance Patterns of Light Neutron-capture Elements in Very-metal-poor Stars
• On the Impact of Neutron Star Binaries Natal-Kick Distribution on the Galactic r-process Enrichment
• GW170817: A Neutron Star Merger in a Mass-Transferring Triple System
• TOF-Brho Mass Measurements of Very Exotic Nuclides for Astrophysical Calculations at the NSCL
• Precision mass measurements of radioactive nuclei at JYFLTRAP

Cited by in corpus (70)

• Nuclear mass predictions with machine learning reaching the accuracy required by $r$-process studies
• The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
• The s Process and Beyond
• Lipkin model on a quantum computer
• Nucleosynthesis and observation of the heaviest elements
• Evaluating Approximate Flavor Instability Metrics in Neutron Star Mergers
• Abundances of disk and bulge giants from high-resolution optical spectra -- IV. Zr, La, Ce, Eu
• Dynamical ejecta of neutron star mergers with nucleonic weak processes II: Kilonova emission
• Sensitivity study of \emph{r}-process abundances to nuclear masses
• OCCASO V. Chemical-abundance trends with Galactocentric distance and age
• r-Process Radioisotopes from Near-Earth Supernovae and Kilonovae
• The stellar beta-decay rate of 134Cs and its impact on the Barium nucleosynthesis in the s process
• Properties of 187Ta revealed through isomeric decay
• Numerical investigation of spallation neutrons generated from petawatt-scale laser-driven proton beams
• Collective neutrino oscillations and heavy-element nucleosynthesis in supernovae: exploring potential effects of many-body neutrino correlations
• Reverse Algols and hydrogen-rich Wolf-Rayet stars from very massive binaries
• Enhanced dynamics in fusion of neutron-rich oxygen nuclei at above-barrier energies
• Neural Network Emulation of Spontaneous Fission
• Nucleosynthesis in outflows of compact objects and detection prospects of associated kilonovae
• Quenching factor of Gamow-Teller and spin dipole giant resonances
• Nuclear states projected from a pair condensate
• Finite-temperature linear response theory based on relativistic Hartree Bogoliubov model with point-coupling interaction
• The Gaia-ESO survey: placing constraints on the origin of r-process elements
• High-precision nuclear chronometer for the cosmos
• A low-metallicity massive contact binary undergoing slow Case A mass transfer: A detailed spectroscopic and orbital analysis of SSN 7 in NGC 346 in the SMC
• Underground laboratory JUNA shedding light on stellar nucleosynthesis
• Isochronic evolution and the radioactive decay of r-process nuclei
• Projected shell model description of nuclear level density: Collective, pair-breaking, and multiquasiparticle regimes in even-even nuclei
• Nuclear level density from relativistic density functional theory and combinatorial method
• On the Habitable Lifetime of Terrestrial Worlds with High Radionuclide Abundances
• Slow Neutron-Capture Process: Low-mass AGB stars and presolar silicon carbide grains
• Non-iterative finite amplitude methods for E1 and M1 giant resonances
• Near-infrared chemical abundances of stars in the Sculptor dwarf galaxy
• Proposed Lunar Measurements of $r$-Process Radioisotopes to Distinguish Origin of Deep-sea 244Pu
• Competition between allowed and first-forbidden $\beta$ decay in $r$-process waiting-point nuclei within a relativistic beyond-mean-field approach
• Correlations between nuclear landscape boundaries and neutron-rich r-process abundances
• Chemical Tagging N-rich Field Stars with High-resolution Spectroscopy
• Impact of level densities and $\gamma$-strength functions on $r$-process simulations
• Gamow-Teller transitions of neutron-rich $N=82,81$ nuclei by shell-model calculations
• Thermonuclear 17O(n,gamma)18O reaction rate and its astrophysical implications
• Nuclear contacts of unstable nuclei
• Correlation between U/Th and Pb/Os abundance ratios and its application in nuclear cosmochronology
• Progress in Nuclear Astrophysics of East and Southeast Asia
• Supernova Preshock Neutronization Burst as a Probe of Non-Standard Neutrino Interactions
• Isovector spin susceptibility: Isotopic evolution of collectivity in spin response
• Ultraheavy Ultrahigh-Energy Cosmic Rays
• Symmetry breaking of Gamow-Teller and magnetic-dipole transitions and its restoration in calcium isotopes
• R-process Nucleosynthesis of Subminimal Neutron Star Explosions
• Impact of nuclear mass models on $r$-process nucleosynthesis and heavy element abundances in $r$-process enhanced metal-poor stars
• Theory of nuclear collective vibrations
• Neutrinos and Heavy Element Nucleosynthesis
• How Do Nuclear Isomers Influence the Gamma-Ray Bursts in Binary Neutron Star Mergers?
• Shell-model study for allowed and forbidden ${\beta }^{-}$ decay properties in the mass region "south" of ${}^{208}$Pb
• Critically Evaluated Atomic Data for Au IV Spectrum
• Detection probability of light compact binary mergers in future observing runs of the current ground-based gravitational wave detector network
• Multimodal fission from self-consistent calculations
• A microscopic calculation of fission cross sections with the non-equilibrium Green function method
• Gamma-ray emission from decays of boosted nuclei in protomagnetar jets
• Exploratory study on the masses of odd-$Z$ nuclei and $r$-process simulation based on the deformed relativistic Hartree-Bogoliubov theory in continuum
• Th/Eu abundance ratio of red giants in the Kepler Field
• Open clusters in the outer disc studied with MEGARA@GTC Auner 1 and Berkeley 102
• Impact of the latest 22Ne+α reaction rates on nucleosynthesis in massive stars and galactic chemical evolution
• Ab initio calculations of beta-decay half-lives for $N=50$ neutron-rich nuclei
• Axially Deformed Proton-Neutron Relativistic Quasiparticle Finite Amplitude Method for Charge-Exchange Transitions
• Limits on active-sterile neutrino mixing parameters using heavy nuclei abundances
• Nuclear data activities for medium mass and heavy nuclei at Los Alamos
• Determining stellar properties of massive stars in NGC346 in the SMC with a Bayesian statistic technique
• Neutrinos in colliding neutron stars and black holes
• Impact of nuclear masses on r-process nucleosynthesis: bulk properties versus shell effects
• Silicon and Strontium abundances of very metal-poor stars determined from near-infrared spectra