10:00 〜 10:15
[PEM11-05] Radiation hydrodynamics simulations of atmospheric escape of metal-rich hot Jupiters
キーワード：ホットジュピター、大気散逸、流体力学
Hot Jupiters are close-in gas giant planets. In order to understand planetary systems in general, including planets in our solar system, it is necessary to understand the formation and evolutionary processes of such close-in planets.
The intense UV radiation can drive atmospheric escape of close-in planets. The escape process is a key process in the evolution of close-in exoplanets. Photoionization heating of hydrogen atoms by extreme-ultraviolet (EUV) radiation with energies above 13.6 eV drives hydrodynamic atmospheric escape. Such atmospheric escape has been observed in some short-period planets using the transit method.
Recent observations of a hot Jupiter, HD 189733 b, have found that the broad band absorption at ∼ 2350 and ∼ 2600 Å. The absorption is consistent with the Feii absorption, but the hydrodynamic models with solar-metallicity can not explain the absorption excess.
We run radiation hydrodynamics simulations of atmospheric escape of hot Jupiters with higher-metallicity to investigate the effect of metals on the escaping outflow and the observed signals.
In the case of super-solar metallicity, the radiative cooling of metal line may reduces the atmospheric escape and the absorption.
We also investigate the effect of aerosols which might be possible absorber. We find that the existence of the aerosols can enhance the atmospheric escape by photoelectric heating. In this case, the far-ultraviolet (FUV) heating may be another heating source. FUV heating may be significant in the case of hot host star. We also run simulations of ultra-hot Jupiters, such as WASP-121b. We find that FUV heating dominates heating rate for close-in planets around hot star.
We discuss the effect of such metals on the thermo-chemical structure of the upper atmosphere and the observational signals.
The intense UV radiation can drive atmospheric escape of close-in planets. The escape process is a key process in the evolution of close-in exoplanets. Photoionization heating of hydrogen atoms by extreme-ultraviolet (EUV) radiation with energies above 13.6 eV drives hydrodynamic atmospheric escape. Such atmospheric escape has been observed in some short-period planets using the transit method.
Recent observations of a hot Jupiter, HD 189733 b, have found that the broad band absorption at ∼ 2350 and ∼ 2600 Å. The absorption is consistent with the Feii absorption, but the hydrodynamic models with solar-metallicity can not explain the absorption excess.
We run radiation hydrodynamics simulations of atmospheric escape of hot Jupiters with higher-metallicity to investigate the effect of metals on the escaping outflow and the observed signals.
In the case of super-solar metallicity, the radiative cooling of metal line may reduces the atmospheric escape and the absorption.
We also investigate the effect of aerosols which might be possible absorber. We find that the existence of the aerosols can enhance the atmospheric escape by photoelectric heating. In this case, the far-ultraviolet (FUV) heating may be another heating source. FUV heating may be significant in the case of hot host star. We also run simulations of ultra-hot Jupiters, such as WASP-121b. We find that FUV heating dominates heating rate for close-in planets around hot star.
We discuss the effect of such metals on the thermo-chemical structure of the upper atmosphere and the observational signals.