Radiating Bondi Flows II: Giant Planet Accretion Models
astro-ph.EP
Submitted: 2026-03-20
Updated: 2026-09-24
Comments: Paper II in a series. See accompanying Paper I for general theory. Accepted by MNRAS
Code: https://github.com/apbailey/radiative-bondi-products
License: http://creativecommons.org/licenses/by/4.0/
The gist: In the core accretion model of giant planet formation, the late stages of runaway growth are regulated by the hydrodynamic infall of gas from the protoplanetary disk.
Terminology
Abstract
In the core accretion model of giant planet formation, the late stages of runaway growth are regulated by the hydrodynamic infall of gas from the protoplanetary disk. For a subset of planet-disk pairings, this scenario is analogous to the classical Bondi problem, which has motivated a Bondi-like parameterization of accretion in some population synthesis models. Existing models and the associated classical Bondi rate however, are predicated upon an adiabatic equation of state. In reality, the planet and its associated accretion shock supply a luminosity that substantially heats the accretion flow. In Paper I of this series, we demonstrate that such radiative feedback can dramatically suppress accretion by orders of magnitude. Here we quantify this effect under realistic planet-forming conditions. We find that for planets forming in an unperturbed disk, accretion is suppressed by 1-2 orders of magnitude interior to about 10 AU. For planets that open a gap, this feedback is less dramatic and the effect is about 1 order in magnitude. We investigate the effect of various assumptions regarding dust opacities, shock efficiency, and planet radius and find this radiative suppression mechanism to be fairly insensitive to these effects. We also perform full time-dependent simulations demonstrating that the associated adverse entropy profiles are accurate and stable to convection. A simple and flexible set of open-source tools are provided to incorporate this radiative feedback into existing accretion models and population synthesis frameworks.
Sources
- Spectral Energy Distributions of Disc-Embedded Accreting Protoplanets
- An Empirical Mass-Radius Relation for Cool Giant Planets
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