Constraints on Bygone Nucleosynthesis of Accreting Neutron Stars

Abstract

Nuclear burning near the surface of an accreting neutron star produces ashes that, when compressed deeper by further accretion, alter the star's thermal and compositional structure. Bygone nucleosynthesis can be constrained by the impact of compressed ashes on the thermal relaxation of quiescent neutron star transients. In particular, Urca cooling nuclei pairs in nuclear burning ashes, which cool the neutron star crust via neutrino emission from electron-capture/beta-decay cycles, provide signatures of prior nuclear burning over the ~century timescales it takes to accrete to the electron-capture depth of the strongest cooling pairs. Using crust cooling models of the accreting neutron star transient MAXI J0556-332, we show that this source likely lacked Type I X-ray bursts and superbursts >120 years ago. Reduced nuclear physics uncertainties in rp-process reaction rates and electron-capture ft-values for low-lying transitions will improve nucleosynthesis constraints using this technique.

arXiv commentAccepted to the Astrophysical Journal

References in corpus (31)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
• The endpoint of the rp process on accreting neutron stars
• Models for Type I X-Ray Bursts with Improved Nuclear Physics
• A Remarkable Three Hour Thermonuclear Burst From 4U 1820-30
• Mapping crustal heating with the cooling lightcurves of quasi-persistent transients
• The rp Process Ashes from Stable Nuclear Burning on an Accreting Neutron Star
• Heating in the Accreted Neutron Star Ocean: Implications for Superburst Ignition
• Crustal Emission and the Quiescent Spectrum of the Neutron Star in KS 1731-260
• Dependence of X-Ray Burst Models on Nuclear Reaction Rates
• X-ray binaries
• Strong neutrino cooling by cycles of electron capture and ${\beta }^{-}$ decay in neutron star crusts
• Periodic Thermonuclear X-ray Bursts from GS 1826-24 and the Fuel Composition as a Function of Accretion Rate
• Models of Type I X-ray Bursts from GS 1826-24: A Probe of rp-Process Hydrogen Burning
• Nucleosynthesis in Type I X-ray Bursts
• Hydrodynamic Models of Type I X-Ray Bursts: Metallicity Effects
• Forecasting neutron star temperatures: predictability and variability
• Time-Variable Emission from Transiently Accreting Neutron Stars In Quiescence due to Deep Crustal Heating
• A strong shallow heat source in the accreting neutron star MAXI J0556-332
• Superburst Models for Neutron Stars with Hydrogen and Helium-Rich Atmospheres
• A strongly heated neutron star in the transient Z source MAXI J0556-332
• Quiescent thermal emission from neutron stars in LMXBs
• Multi-Zone Models of Superbursts from Accreting Neutron Stars
• Urca cooling pairs in the neutron star ocean and their effect on superbursts
• Reaction Rate and Composition Dependence of the Stability of Thermonuclear Burning on Accreting Neutron Stars
• Mass measurement of 56Sc reveals a small A=56 odd-even mass staggering, implying a cooler accreted neutron star crust
• Spectral Evolution of a New X-ray Transient MAXI J0556-332 Observed by MAXI, Swift, and RXTE
• Carbon production on accreting neutron stars in a new regime of stable nuclear burning
• The nature of the X-ray transient MAXI J0556-332

Cited by in corpus (19)

• Nuclear Physics of the Outer Layers of Accreting Neutron Stars
• Cooling of Accretion-Heated Neutron Stars
• Nuclear Reactions in the Crusts of Accreting Neutron Stars
• Influence of Nuclear Reaction Rate Uncertainties on Neutron Star Properties Extracted From X-ray Burst Model-Observation Comparisons
• Consistent Modeling of GS 1826-24 X-ray Bursts for Multiple Accretion Rates Demonstrates the Possibility to Constrain rp-process Reaction Rates
• Horizons: Nuclear Astrophysics in the 2020s and Beyond
• Nuclear Mass Measurements Map the Structure of Atomic Nuclei and Accreting Neutron Stars
• First direct measurement of ${}^{22}$Mg($\alpha$,p)${}^{25}$Al and implications for X-ray burst model-observation comparisons
• Urca Cooling in Neutron Star Crusts and Oceans: Effects of Nuclear Excitations
• $\beta$-decay of ${}^{61}$V and its Role in Cooling Accreted Neutron Star Crusts
• Neutron transfer reactions in accreting neutron stars
• The Impacts of Neutron-Star Structure and Base Heating on Type I X-Ray Bursts and Code Comparison
• Crust Cooling Models are Insensitive to the Crust-Core Transition Pressure for Realistic Equations of State
• Improved Nuclear Physics Near $A=61$ Refines Urca Neutrino Luminosities in Accreted Neutron Star Crusts
• Spallation-altered accreted compositions for X-ray bursts: Impact on ignition conditions and burst ashes
• Constraining Accreted Neutron Star Crust Shallow Heating with the Inferred Depth of Carbon Ignition in X-ray Superbursts
• Weak interaction rates of $sd$-shell Urca pairs in stellar environment using a shell-model approach
• The Great Wall: Urca Cooling Layers in the Accreted NS Crust
• Urca Nuclide Production in Type-I X-ray Bursts and Implications for Nuclear Physics Studies