radbondi 0.3.0

Time-dependent spherical Bondi accretion with radiative cooling

radbondi

Time-dependent spherical Bondi accretion with radiative cooling.

radbondi solves the 1D spherical Euler equations with an implicit cooling source term, evolving the flow from an initial adiabatic Bondi profile to a self-consistent steady state. It is designed for problems where the standard ODE shooting method fails — e.g., when cooling is strong enough that the sonic point becomes a focus (complex eigenvalues) rather than a saddle.

The default microphysics (relativistic bremsstrahlung + e⁺e⁻ and μ⁺μ⁻ pair annihilation) targets accretion onto compact objects in hot, dense environments such as stellar interiors, but the cooling module is plug-in: users can add their own processes by subclassing CoolingProcess.

Status

Alpha. API may change. See CHANGELOG.md for releases.

Installation

pip install -e ".[dev]"   # development install

Quickstart

import radbondi as rb

ambient = rb.presets.solar_core()
problem = rb.BondiProblem(M_BH=1e-16 * rb.M_sun, ambient=ambient)
sol = problem.solve(rb.SolverConfig(N=800, x_min=3e-6))

print(f"eta = {sol.eta:.3e}")
sol.plot_profiles()

Documentation

See the docs/ directory:

• usage.md — installation, quickstart, API, and all SolverConfig knobs.
• physics.md — equations, Bondi solution, microphysics, and feedback models.
• scheme.md — finite-volume discretization, well-balancing, and implicit cooling.

Citation

If you use radbondi in published work, please cite both the software and the paper describing the underlying physics. See CITATION.cff for machine-readable metadata; GitHub renders a "Cite this repository" button on the project page.

Cantiello et al. (in prep.)

License

MIT — see LICENSE.