相关论文: Photo-ionization of planetary winds: case study HD…
Radiative transfer in planetary atmospheres is usually treated in the static limit, i.e., neglecting atmospheric motions. We argue that hot Jupiter atmospheres, with possibly fast (sonic) wind speeds, may require a more strongly coupled…
We develop a flexible one-dimensional code to model the escape of hydrogen and helium from a hot Jupiter as a result of photoionization from extreme-ultraviolet (EUV) radiation. We include stellar spectrum heating and ionization, radiative…
We present a new, on-the-fly photon flux and absorption tracer algorithm designed to directly measure the contribution of different source populations to the metagalactic UV background and to the ionisation fraction of gas in the Universe.…
The atmosphere of the exoplanet HD 209458b is undergoing sustained mass loss, believed to be caused by X-ray and extreme-ultraviolet (XUV) irradiation from its star. The majority of this flux is not directly observable due to interstellar…
We employ a two-dimensional grid-based hydrodynamic model to simulate upper atmospheric dynamics on extrasolar giant planets. Our model is well-suited to simulate the dynamics of the atmospheres of planets with high orbital eccentricity…
We simulate the space environment around AU Microscopii b and the interaction between the magnetized stellar wind with a planetary atmospheric outflow for ambient stellar wind conditions and Coronal Mass Ejection (CME) conditions. We also…
Hot Jupiters might reside inside the Alfv\'en surface of their host star wind, where the stellar wind is dominated by magnetic energy. The implications of such a sub-Alfv\'enic environment for atmospheric escape are not fully understood.…
The growth of spectroscopic observations of exoplanetary systems allows the possibility of testing theoretical models and studying the interaction that exoplanetary atmospheres have with the wind and the energetic photons from the star. In…
We use the photon flux and absorption tracer algorithm presented in Katz et al.~2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a…
We develop a general method for the self consistent calculation of the hydrodynamics of an astrophysical object irradiated by a radiation field with an arbitrary strength and spectral energy distribution (SED). Using the XSTAR…
Transit observations of HD 209458b in the stellar Lyman-$\alpha$ (Ly$\alpha$) line revealed strong absorption in both blue and red wings of the line interpreted as hydrogen atoms escaping from the planet's exosphere at high velocities. The…
Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e., the stellar wind) much denser than the local conditions encountered around the solar system planets. The environment surrounding these exoplanets…
We present a detailed three-dimensional radiative-hydrodynamical simulation of the well known irradiated exoplanet HD189733b. Our model solves the fully compressible Navier-Stokes equations coupled to wavelength-dependent radiative transfer…
Photoionization modelling allows to follow the transport, the emergence, and the absorption of photons taking into account all important processes in nebular plasmas. Such modelling needs the spatial distribution of density, chemical…
Similar to the case of solar system planets, reflected starlight from exoplanets is expected to be polarized due to atmospheric scattering and the net disk integrated polarization should be non-zero owing to the asymmetrical illumination of…
Improving upon our purely dynamical work, we present three-dimensional simulations of the atmospheric circulation on Earth-like (exo)planets and hot Jupiters using the GFDL-Princeton Flexible Modeling System (FMS). As the first steps away…
Aims: We aim at constraining the conditions of the wind and high-energy emission of the host star reproducing the non-detection of Ly$\alpha$ planetary absorption. Methods: We model the escaping planetary atmosphere, the stellar wind, and…
One of the most well-studied exoplanets to date, HD 189733 b, stands out as an archetypal hot Jupiter with many observations and theoretical models aimed at characterizing its atmosphere, interior, host star, and environment. We report here…
Recent observations of planetary atmospheres in HAT-P-32 b and HAT-P-67 b reveal extensive outflows reaching up to hundreds of planetary radii. The helium 1083 nm light curves for these planets, captured across their full orbits, show…
We provide a brief review of the physical processes behind the radiative driving of the winds of OB stars and the Bondi-Hoyle-Lyttleton capture and accretion of a fraction of the stellar wind by a compact object, typically a neutron star,…