Hydrodynamical simulations of proton ingestion flashes in Type I X-ray Bursts
arXiv:2405.08952 · doi:10.3847/1538-4357/ad81f7
Abstract
We perform the first multidimensional fluid simulations of thermonuclear helium ignition underneath a hydrogen-rich shell. This situation is relevant to Type I X-ray bursts on neutron stars that accrete from a hydrogen-rich companion. Using the low Mach number fluid code MAESTROeX, we investigate the growth of the convection zone due to nuclear burning, and the evolution of the chemical abundances in the atmosphere of the star. We also examine the convective boundary mixing processes that cause the evolution to differ significantly from previous one-dimensional simulations that rely on mixing-length theory. We find that the convection zone grows outwards as penetrating fluid elements cool the overlying radiative layer, rather than directly from the increasing entropy of the convection zone itself. Simultaneously, these flows efficiently mix composition, carrying carbon out of, and protons into the convection zone even before contact with the hydrogen shell. We discuss the implications of these effects for future modeling of these events and observations.
arXiv comment14 pages, 7 figures. New section with more explosive burst since first arxiv version. Published in ApJ (November 2024)
References in corpus (31)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- Array Programming with NumPy
- Modules for Experiments in Stellar Astrophysics (MESA)
- Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
- A Multi-Code Analysis Toolkit for Astrophysical Simulation Data
- Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
- Models for Type I X-Ray Bursts with Improved Nuclear Physics
- CASTRO: A New Compressible Astrophysical Solver. I. Hydrodynamics and Self-Gravity
- Convective-reactive proton-C12 combustion in Sakurai's object (V4334 Sagittarii) and implications for the evolution and yields from the first generations of stars
- Simulations of core convection in rotating A-type stars: Differential rotation and overshooting
- Rotational Evolution During Type I X-Ray Bursts
- Exposing the Nuclear Burning Ashes of Radius Expansion Type I X-ray Bursts
- Low Mach Number Modeling of Type Ia Supernovae
- The Multi-INstrument Burst ARchive (MINBAR)
- Hydrodynamic Models of Type I X-Ray Bursts: Metallicity Effects
- MAESTRO: An Adaptive Low Mach Number Hydrodynamics Algorithm for Stellar Flows
- Evidence of heavy-element ashes in thermonuclear X-ray bursts with photospheric superexpansion
- A NICER thermonuclear burst from the millisecond X-ray pulsar SAX J1808.4-3658
- Flame Propagation on the Surfaces of Rapidly Rotating Neutron Stars during Type I X-ray Bursts
- Multidimensional Modeling of Type I X-ray Bursts. I. Two-Dimensional Convection Prior to the Outburst of a Pure Helium Accretor
- Convective boundary mixing in main-sequence stars: theory and empirical constraints
- Detection of burning ashes from thermonuclear X-ray bursts
- Multidimensional Modeling of Type I X-ray Bursts. II. Two-Dimensional Convection in a Mixed H/He Accretor
- MAESTROeX: A Massively Parallel Low Mach Number Astrophysical Solver
- NICER Discovers Spectral Lines During Photospheric Radius Expansion Bursts from 4U 1820-30: Evidence for Burst-driven Winds
- Low Mach number modeling of Type I X-ray burst deflagrations
- Super-Eddington winds from Type I X-ray bursts
- Dynamics of Laterally Propagating Flames in X-ray Bursts. I. Burning Front Structure
- The imprint of convection on Type I X-ray bursts: Pauses in photospheric radius expansion lightcurves
- Thermal convection in rotating spherical shells: temperature-dependent internal heat generation using the example of triple- burning in neutron stars
- Simulating Lateral H/He Flame Propagation in Type I X-ray Bursts