相关论文: Simulating the escaping atmospheres of hot gas pla…
We study roles of the thermosphere and exosphere on the Martian ionospheric structure and ion escape rates in the process of the solar wind-Mars interaction. We employ a four-species multifluid MHD (MF-MHD) model to simulate the Martian…
We examine changes in the molecular abundances resulting from increased heating due to a self-luminous planetary companion embedded within a narrow circumstellar disk gap. Using 3D models that include stellar and planetary irradiation, we…
Throughout their lives, short period exoplanets (<100 days) experience X-ray and extreme-UV (XUV) stellar irradiation that can heat and photoionize planets' upper atmospheres, driving transonic outflows. This photoevaporative mass loss…
Transiting planets provide a unique opportunity to study the atmospheres of extra-solar planets. Radiative hydrodynamical models of the atmosphere provide a crucial link between the physical characteristics of the atmosphere and the…
We present a coupled 3-D atmospheric dynamics and radiative transfer model to predict the disk-integrated thermal emission spectra of transiting exoplanets in edge-on orbits. We calculate spectra at high resolution to examine the extent to…
Atmospheric escape of planets on short orbital periods, driven by the host star's irradiation, influences their evolution, composition, and atmospheric dynamics. Our main avenue to probe atmospheric escape is through the near-infrared…
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…
Of the over 200 known extrasolar planets, 14 exhibit transits in front of their parent stars as seen from Earth. Spectroscopic observations of the transiting planets can probe the physical conditions of their atmospheres. One such technique…
Planetary habitability is in part determined by the atmospheric evolution of a planet; one key component of such evolution is escape of heavy ions to space. Ion loss processes are sensitive to the plasma environment of the planet, dictated…
The classical picture of our Solar System being the archetypal outcome of planet formation has been rendered obsolete by the astonishing diversity of extrasolar-system architectures. From rare hot-Jupiters to abundant super-Earths and…
We have developed a pseudo two-dimensional model of a planetary atmosphere, which takes into account thermochemical kinetics, photochemistry, vertical mixing, and horizontal transport, the latter being modeled as a uniform zonal wind. We…
We calculated an atmospheric grid for hot mini-Neptune and giant exoplanets, that links astrophysical observable parameters- orbital distance and stellar type- with the chemical atmospheric species expected. The grid can be applied to…
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:…
We investigate roles of Alfvenic waves in the weakly-ionized atmosphere of hot Jupiters by carrying out non-ideal magnetohydrodynamic (MHD) simulations with Ohmic diffusion in one-dimensional magnetic flux tubes. Turbulence at the surface…
Warm rocky exoplanets within the habitable zone of Sun-like stars are favoured targets for current and future missions. Theory indicates these planets could be wet at formation and remain habitable long enough for life to develop. In this…
Multi-band phase variations in principle allow us to infer the longitudinal temperature distributions of planets as a function of height in their atmospheres. For example, 3.6 micron emission originates from deeper layers of the atmosphere…
The warm Neptune GJ436b was observed with HST/STIS at three different epochs in the stellar Ly-alpha line, showing deep, repeated transits caused by a giant exosphere of neutral hydrogen. The low radiation pressure from the M-dwarf host…
The recent transit observation of HD 209458 b - an extrasolar planet orbiting a sun-like star - confirmed that it is a gas giant and determined that its orbital inclination is 85 degrees. This inclination makes possible investigations of…
The K2-33 planetary system hosts one transiting ~5 R_E planet orbiting the young M-type host star. The planet's mass is still unknown, with an estimated upper limit of 5.4 M_J. The extreme youth of the system (<20 Myr) gives the…
We study the interaction between stellar irradiation and tidal heating in gaseous planets with short orbital periods. The intentionally simplified atmospheric model we employ makes the problem analytically tractable and permits the…