Exploring the catastrophic regime: thermodynamics and disintegration in head-on planetary collisions

Abstract

Head-on giant impacts (collisions between planet-size bodies) are frequently used to study the planet formation process as they present an extreme configuration where the two colliding bodies are greatly disturbed. With limited computing resources, focusing on these extreme impacts eases the burden of exploring a large parameter space. Results from head-on impacts are often then extended to study oblique impacts with angle corrections or used as initial conditions for other calculations, for example, the evolution of ejected debris. In this study, we conduct a detailed investigation of the thermodynamic and energy budget evolution of high-energy head-on giant impacts, entering the catastrophic impacts regime, for target masses between 0.001 and 12 M${}_{\oplus }$. We demonstrate the complex interplay of gravitational forces, shock dynamics, and thermodynamic processing in head-on impacts at high energy. Our study illustrates that frequent interactions of core material with the liquid side of the vapour curve could have cumulative effects on the post-collision remnants, leading to fragmentary disintegration occurring at lower impact energy. This results in the mass of the largest remnant diverging significantly from previously developed scaling laws. These findings suggest two key considerations: 1) head-on planetary collisions for different target masses do not behave similarly, so caution is needed when applying scaling laws across a broad parameter space; 2) an accurate model of the liquid-vapour phase boundary is essential for modeling giant impacts. Our findings highlight the need for careful consideration of impact configurations in planetary formation studies, as head-on impacts involve a complex interplay between thermodynamic processing, shocks, gravitational forces, and other factors.

Published in MNRAS, 25 pages, 21 figures

References in corpus (33)

• GIZMO: A New Class of Accurate, Mesh-Free Hydrodynamic Simulation Methods
• Improving convergence in smoothed particle hydrodynamics simulations without pairing instability
• Smoothed Particle Hydrodynamics and Magnetohydrodynamics
• Collisions between Gravity-Dominated Bodies: 2. The Diversity of Impact Outcomes during the End Stage of Planet Formation
• Collisions Between Gravity-Dominated Bodies: 1. Outcome Regimes and Scaling Laws
• The origin of the Moon within a terrestrial synestia
• Collisional Stripping and Disruption of Super-Earths
• A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system
• SWIFT: A modern highly-parallel gravity and smoothed particle hydrodynamics solver for astrophysical and cosmological applications
• Investigation of the Initial State of the Moon-Forming Disk: Bridging SPH Simulations and Hydrostatic Models
• Forming Mercury by Giant Impacts
• Consequences of Giant Impacts on Early Uranus for Rotation, Internal Structure, Debris, and Atmospheric Erosion
• Bifurcation in the history of Uranus and Neptune: the role of giant impacts
• Numerical aspects of Giant Impact simulations
• Planetary Giant Impacts: Convergence of High-Resolution Simulations using Efficient Spherical Initial Conditions and SWIFT
• The Shock Physics of Giant Impacts: Key Requirements for the Equations of State
• Collisional stripping of planetary crusts
• Atmospheric Erosion by Giant Impacts onto Terrestrial Planets
• Atmosphere loss in planet-planet collisions
• A super-massive Neptune-sized planet
• Immediate origin of the Moon as a post-impact satellite
• Realistic On-The-Fly Outcomes of Planetary Collisions: Machine Learning Applied to Simulations of Giant Impacts
• Enhanced mixing in giant impact simulations with a new Lagrangian method
• A recent impact origin of Saturn's rings and mid-sized moons
• Forming Iron-rich Planets with Giant Impacts
• The effect of pre-impact spin on the Moon-forming collision
• Atmosphere Loss in Oblique Super-Earth Impacts
• The EOS/Resolution Conspiracy: Convergence in Proto-Planetary Collision Simulations
• Planetary Embryo Collisions and the Wiggly Nature of Extreme Debris Disks
• Effect of Equation of State and Cutoff Density in Smoothed Particle Hydrodynamics Simulations of the Moon-Forming Giant Impact
• Residual Neural Networks for the Prediction of Planetary Collision Outcomes
• Exploring the catastrophic regime: thermodynamics and disintegration in head-on planetary collisions
• Isolating the extreme debris disc signature -- explorations of eccentric extreme debris discs formed by giant impacts

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