Electron capture in stars

Abstract

Electron captures on nuclei play an essential role for the dynamics of several astrophysical objects. The capture rate can be derived in perturbation theory where allowed nuclear transitions (Gamow-Teller transitions) dominate, except at the higher temperatures achieved in core-collapse supernovae where also forbidden transitions contribute significantly to the rates. There has been decisive progress in recent years in measuring Gamow-Teller (GT) strength distributions using novel experimental techniques based on charge-exchange reactions. These measurements provide not only data for the GT distributions of ground states for many relevant nuclei, but also serve as valuable constraints for nuclear models which are needed to derive the capture rates for the many nuclei, for which no data exist yet. In particular models are needed to evaluate the stellar capture rates at finite temperatures, where the capture can also occur on excited nuclear states. There has also been significant progress in recent years in the modelling of stellar capture rates. This has been made possible by advances in nuclear many-body models as well as in computer soft- and hardware. Specifically to derive reliable capture rates for core-collapse supernovae a dedicated strategy has been developed based on a hierarchy of nuclear models specifically adapted to the abundant nuclei and astrophysically conditions present at the various collapse conditions. This manuscript reviews the experimental and theoretical progress achieved recently in deriving stellar electron capture rates. It also discusses the impact these improved rates have on the various astrophysical objects. (Abridged)

64 pages, 24 figures, Review article submitted to Reports on Progress in Physics

References in corpus (28)

• Origin of the heavy elements in binary neutron-star mergers from a gravitational wave event
• Theory of Core-Collapse Supernovae
• Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
• Core-Collapse Supernova Explosion Theory
• Supernova Neutrino Detection
• Hydrodynamics of core-collapse supernovae and their progenitors
• Remnants and ejecta of thermonuclear electron-capture supernovae: Constraining oxygen-neon deflagrations in high-density white dwarfs
• On the extraction of weak transition strengths via the (3He,t) reaction at 420 MeV
• Stellar electron-capture rates calculated with the finite-temperature relativistic random-phase approximation
• Superburst Models for Neutron Stars with Hydrogen and Helium-Rich Atmospheres
• Nucleosynthesis imprints from different Type Ia Supernova explosion scenarios and implications for galactic chemical evolution
• Comparing treatments of weak reactions with nuclei in simulations of core-collapse supernovae
• Measurement of the Gamow-Teller Strength Distribution in 58Co via the 58Ni(t,3He) reaction at 115 MeV/nucleon
• The Importance of Urca-process Cooling in Accreting ONe White Dwarfs
• Gamow-Teller Unit Cross Sections for (t,3He) and (3He,t) Reactions
• The role of weak interactions in dynamic ejecta from binary neutron star mergers
• Modification of the Brink-Axel Hypothesis for High Temperature Nuclear Weak Interactions
• Impact of New Gamow-Teller Strengths on Explosive Type Ia Supernova Nucleosynthesis
• Unblocking of stellar electron capture for neutron-rich $N=50$ nuclei at finite temperature
• Stellar electron capture rates on neutron-rich nuclei and their impact on core-collapse
• Gamow-Teller transitions to 64-Cu measured using the 64-Zn(t,3-He) reaction
• Electron fraction constraints based on Nuclear Statistical Equilibrium with beta equilibrium
• Gamow-Teller strength for the analog transitions to the first T=1/2, J^pi=3/2- states in 13C and 13N and the implications for Type Ia supernovae
• Electron Captures on ${}^{14}\mathrm{N}$ as a Trigger for Helium Shell Detonations
• Impact of complex many-body correlations on electron capture in thermally excited nuclei around ${}^{78}$Ni
• Type Ia Supernovae keep memory of their progenitor metallicity
• Sensitivity of Type Ia supernovae to electron capture rates
• Electron Capture Strength for {60,62}Ni and {58,60,62,64}Ni(p,n){58,60,62,64}Cu reactions at 134.3 MeV

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