Evidence of energy-, recombination-, and photon-limited escape regimes in giant planet H/He atmospheres

Abstract

Hydrodynamic escape is the most efficient atmospheric mechanism of planetary mass loss and has a large impact on planetary evolution. Three hydrodynamic escape regimes have been identified theoretically: energy-limited, recombination-limited, and photon-limited. However, no evidence of these regimes had been reported until now. Here, we report evidence of these three regimes via an analysis of helium I triplet at 10830 angstroms and Ly-$\alpha$ absorption involving a 1D hydrodynamic model that allows us to estimate hydrogen recombination and advection rates. In particular, we show that HD 209458 b is in the energy-limited regime, HD 189733 b is in the recombination-limited regime, and GJ 3470 b is in the photon-limited regime. These exoplanets can be considered as benchmark cases for their respective regimes.

Accepted to A&A. 9 Pages

References in corpus (12)

• Atmospheric Escape from Hot Jupiters
• Improved parameters for extrasolar transiting planets
• Roche lobe effects on the atmospheric loss of "Hot Jupiters"
• Hubble PanCET: An extended upper atmosphere of neutral hydrogen around the warm Neptune GJ 3470 b
• Heating efficiency in hydrogen-dominated upper atmospheres
• Hubble Space Telescope detection of oxygen in the atmosphere of exoplanet HD189733b
• Modelling the He I triplet absorption at 10830 Angstroms in the atmosphere of HD 209458 b
• Benchmarking the power of amateur observatories for TTV exoplanets detection
• A He I upper atmosphere around the warm Neptune GJ 3470b
• Rapid escape of ultra-hot exoplanet atmospheres driven by Hydrogen Balmer absorption
• Modelling the He I triplet absorption at 10830 Angstroms in the atmospheres of HD 189733 b and GJ 3470 b
• Coupled Thermal and Compositional Evolution of Photo Evaporating Planet Envelopes

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• H$\alpha$ and He I absorption in HAT-P-32 b observed with CARMENES -- Detection of Roche lobe overflow and mass loss
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• Characterisation of the upper atmospheres of HAT-P-32 b, WASP-69 b, GJ 1214 b, and WASP-76 b through their He I triplet absorption
• The MOPYS project: A survey of 70 planets in search of extended He I and H atmospheres. No evidence of enhanced evaporation in young planets
• More Evidence for Variable Helium Absorption from HD 189733b
• The open-source sunbather code: modeling escaping planetary atmospheres and their transit spectra
• Confirmation of an He I evaporating atmosphere around the 650-Myr-old sub-Neptune HD235088 b (TOI-1430 b) with CARMENES
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• The influence of host star activity evolution on the population of super-Earths and mini-Neptunes
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• Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou
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• Detectability of Emission from Exoplanet Outflows Calculated by pyTPCI, a New 1D Radiation-Hydrodynamic Code
• Revisiting the atmosphere of HAT-P-70b with CARMENES high-resolution transmission spectroscopy
• A Search for Planetary Metastable Helium Absorption in the V1298 Tau System
• CARMENES detection of the CaII infrared triplet and possible evidence of HeI in the atmosphere of WASP-76b