TRINITY: A coupled model of winds, radiation, and photoionised gas in molecular clouds. I. Methods and validation
Abstract
Multi-wavelength surveys place cloud dispersal at 1-5 Myr after massive stars emerge, before the first supernovae. Whether a cloud disperses, re-collapses, or leaks Lyman-continuum (LyC) photons depends on how pre-supernova winds, radiation pressure, and photoionised-gas pressure (PHII) couple to the shell. We introduce TRINITY, a 1D thin-shell code that succeeds WARPFIELD. TRINITY evolves the bubble-shell structure under winds, supernovae, direct and dust-reprocessed radiation pressure, PHII, and gravity. A phase-aware prescription drives the shell with the larger of the hot-bubble and photoionised pressures when energy-driven, and PHII plus ram pressure when momentum-driven. The initial cloud may be uniform, a piecewise power law, or a Bonnor-Ebert sphere; shell structure, hot-bubble cooling, photon absorption, and LyC escape evolve with the dynamics. We validate against analytic wind and photoionisation limits and survey clouds of mass 105-106.5 M⊙, core density 103-104 cm−3, and star-formation efficiency ε=0.01-$0.30$. PHII enlarges the shell radius by roughly 17% at 10 Myr in the fiducial run. At higher efficiency, the energy-driven phase lasts under 1 Myr, radiation pressure stays sub-dominant, and PHII remains dynamically important in the momentum-driven phase. Cloud structure sets both phase durations and outcomes: at fixed mass, core density, and efficiency, homogeneous and shallow clouds re-collapse while a steep ρ∝ r−2 cloud keeps expanding, and Bonnor-Ebert clouds disperse roughly 55% later than homogeneous ones. Thus PHII and cloud structure both shape feedback-driven expansion even when the stellar population is fixed. TRINITY is an efficient, interpretable framework to map feedback dominance across cloud parameter space and resolved H II regions.
Versions
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BibTeX
@misc{teh2026trinity,
title = {{TRINITY: A coupled model of winds, radiation, and photoionised gas in molecular clouds. I. Methods and validation}},
author = {Jia Wei Teh and Ralf S. Klessen and Simon C. O. Glover and Kathryn Kreckel},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2605.27517},
eprint = {2605.27517},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.27517},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - TRINITY: A coupled model of winds, radiation, and photoionised gas in molecular clouds. I. Methods and validation
AU - Jia Wei Teh
AU - Ralf S. Klessen
AU - Simon C. O. Glover
AU - Kathryn Kreckel
PY - 2026
DA - 2026/08/27
PB - arXiv
DO - 10.48550/arxiv.2605.27517
UR - https://arxiv.org/abs/2605.27517
AB - Multi-wavelength surveys place cloud dispersal at 1-5 Myr after massive stars emerge, before the first supernovae. Whether a cloud disperses, re-collapses, or leaks Lyman-continuum (LyC) photons depends on how pre-supernova winds, radiation pressure, and photoionised-gas pressure (P_HII) couple to the shell. We introduce TRINITY, a 1D thin-shell code that succeeds WARPFIELD. TRINITY evolves the bubble-shell structure under winds, supernovae, direct and dust-reprocessed radiation pressure, P_HII, and gravity. A phase-aware prescription drives the shell with the larger of the hot-bubble and photoionised pressures when energy-driven, and P_HII plus ram pressure when momentum-driven. The initial cloud may be uniform, a piecewise power law, or a Bonnor-Ebert sphere; shell structure, hot-bubble cooling, photon absorption, and LyC escape evolve with the dynamics. We validate against analytic wind and photoionisation limits and survey clouds of mass 10^5-10^6.5 M_⊙, core density 10^3-10^4 cm^−3, and star-formation efficiency ε=0.01-$0.30$. P_HII enlarges the shell radius by roughly 17% at 10 Myr in the fiducial run. At higher efficiency, the energy-driven phase lasts under 1 Myr, radiation pressure stays sub-dominant, and P_HII remains dynamically important in the momentum-driven phase. Cloud structure sets both phase durations and outcomes: at fixed mass, core density, and efficiency, homogeneous and shallow clouds re-collapse while a steep ρ∝ r^−2 cloud keeps expanding, and Bonnor-Ebert clouds disperse roughly 55% later than homogeneous ones. Thus P_HII and cloud structure both shape feedback-driven expansion even when the stellar population is fixed. TRINITY is an efficient, interpretable framework to map feedback dominance across cloud parameter space and resolved H II regions.
ER -