相关论文: Conservation of Total Escape from Hydrodynamic Pla…
The most productive tracer of exoplanetary atmospheric escape is the measurement of excess absorption in the near-infrared metastable helium triplet during transits. Atmospheric escape of a close-in planet's atmosphere plays a role in its…
The bolometric radiation from a central body is potentially a powerful driver of atmospheric escape from planets or satellites. When heated above their equilibrium temperatures those satellites, due to their low surface gravity, are be…
The planets of the Solar System divide neatly between those with atmospheres and those without when arranged by insolation ($I$) and escape velocity ($v_{\mathrm{esc}}$). The dividing line goes as $I \propto v_{\mathrm{esc}}^4$. Exoplanets…
Strong atmospheric escape has been detected in several close-in exoplanets. As these planets consist mostly of hydrogen, observations in hydrogen lines, such as Ly-alpha and H-alpha, are powerful diagnostics of escape. Here, we simulate the…
There is growing observational and theoretical evidence suggesting that atmospheric escape is a key driver of planetary evolution. Commonly, planetary evolution models employ simple analytic formulae (e.g., energy limited escape) that are…
In the present chapter we present the results of evolutionary studies of exoplanetary atmospheres. We mostly focus on the sub- to super-Earth domain, although these methods are applicable to all types of exoplanets. We consider both thermal…
We explore atmospheric escape from close-in exoplanets with the highest mass loss rates. First, we locate the transition from stellar X-ray and UV-driven escape to rapid Roche lobe overflow, which occurs once the 10-100 nbar pressure level…
The hydrodynamic escape driven by external or internal energy sources sculpts the population of low mass close-in planets. However, distinguishing between the driving mechanisms responsible for the hydrodynamic escape of hydrogen-rich…
The recently discovered low-density "super-Earths" Kepler-11b, Kepler-11f, Kepler-11d, Kepler-11e, and planets such as GJ 1214b represent most likely planets which are surrounded by dense H/He envelopes or contain deep H2O oceans also…
Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study…
Gas planets in close proximity to their host stars experience photoevaporative mass loss. The energy-limited escape concept is generally used to derive estimates for the planetary mass-loss rates. Our photoionization hydrodynamics…
When exposed to the high energy X-ray and ultraviolet radiation of a very active star, water vapor in the upper atmospheres of planets can be photodissociated and rapidly lost to space. In this paper, I study the chemical, thermal, and…
Stellar high-energy radiation (X-ray and extreme ultraviolet, XUV) drives atmospheric escape in close-in exoplanets. Given that stellar irradiation depends on the stellar magnetism and that stars have magnetic cycles, we investigate how…
We apply hydrodynamic evaporation models to different synthetic planet populations that were obtained from a planet formation code based on a core-accretion paradigm. We investigated the evolution of the planet populations using several…
Hydrodynamic atmospheric escape plays a central role in shaping the demographics of small, close-in exoplanets. Two mechanisms have been proposed to drive mass loss: photoevaporation, powered by UV irradiation, and core-powered mass loss,…
The recent discoveries of terrestrial exoplanets and super-Earths extending over a broad range of orbital and physical parameters suggest that these planets will span a wide range of climatic regimes. Characterization of the atmospheres of…
JWST observations of the 7-planet TRAPPIST-1 system will provide an excellent opportunity to test outcomes of stellar-driven evolution of terrestrial planetary atmospheres, including atmospheric escape, ocean loss and abiotic oxygen…
We present here results of numerical simulations of the formation and early evolution of rocky planets through pebble accretion, with an with an emphasis on hydrogen envelope longevity and the composition of the outgassed atmosphere. We…
Planetary embryos form protoplanets via mutual collisions, which can lead to the development of magma oceans. During their solidification, large amounts of the mantles' volatile contents may be outgassed. The resulting H$_2$O/CO$_2$…
Transiting exoplanets provide detailed access to their atmospheres, as the planet's signal can be effectively separated from that of its host star. For transiting exoplanets three fundamental atmospheric measurements are possible:…