Related papers: Estimating Ion Escape from Unmagnetized Planets
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 climate of Mars likely evolved from a warmer, wetter early state to the cold, arid current state. However, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements…
We briefly review the various proposed scenarios that may lead to nonthermal radio emissions from exoplanetary systems (planetary magnetospheres, magnetosphere-ionosphere and magnetosphere-satellite coupling, and star-planet interactions),…
With a Monte-Carlo model we investigate the escape of hot oxygen and carbon from the martian atmosphere for four points in time in its history corresponding to 1, 3, 10, and 20 times the present solar EUV flux. We study and discuss…
In this paper, we estimate the X-ray emission from close-in exoplanets. We show that the Solar/Stellar Wind Charge Exchange Mechanism (SWCX) which produces soft X-ray emission is very effective for hot Jupiters. In this mechanism, X-ray…
Escape of an early atmosphere from Titan, during which time NH3 could be converted by photolysis into the present N2 dominated atmosphere, is an important problem in planetary science. Recently Gilliam and Lerman (2014) estimated escape…
In this paper we calculate the escape fraction ($f_{\rm esc}$) of ionizing photons from starburst galaxies. Using 2-D axisymmetric hydrodynamic simulations, we study superbubbles created by overlapping supernovae in OB associations. We…
We use 3D hydrodynamics simulations followed by synthetic line profile calculations to examine the effect increasing the strength of the stellar wind has on observed Ly-$\alpha$ transits of a Hot Jupiter (HJ) and a Warm Neptune (WN). We…
The escape fraction of ionizing photons from galaxies is a crucial quantity controlling the cosmic ionizing background radiation and the reionization. Various estimates of this parameter can be obtained in the redshift range, z=0--6, either…
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…
Exoplanets with substantial Hydrogen/Helium atmospheres have been discovered in abundance, many residing extremely close to their parent stars. The extreme irradiation levels these atmospheres experience causes them to undergo hydrodynamic…
The ambipolar electrostatic field has long been recognized as a key driver of ion escape from planetary atmospheres. Elucidating the mechanisms responsible for the generation of this field is critical for understanding atmospheric escape…
A combined fluid/kinetic model is developed to calculate thermally driven escape of N2 from Pluto's atmosphere for two solar heating conditions: no heating above 1450 km and solar minimum heating conditions. In the combined model,…
An extended XMM-Newton observation of the Seyfert 1 galaxy NGC 4051 in 2009 revealed an unusually rich absorption spectrum with outflow velocities, in both RGS and EPIC spectra, up to ~ 9000 km/s (Pounds and Vaughan 2011). Evidence was…
Hydrogen loss to space is a key control on the evolution of the Martian atmosphere and the desiccation of the red planet. Thermal escape is thought to be the dominant loss process, but both forward modeling studies and remote sensing…
In connection with the exit of mankind and its production into open space, the problem of the nature of solar wind (SW) is acute. We have proved that a nonequilibrium inhomogeneous giant gas discharge with huge values of the E/N parameter,…
We seek to characterize giant-planet systems by their gravitational scattering properties. We do this to a given system by integrating it numerically along with a large number of hypothetical small bodies that are initially in eccentric…
The response of Martian ionosphere to the passage of Corotating Interaction Region (CIR) of June 2015 is studied using observations from several instruments aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. An intense CIR…
Accurately predicting the z-component of the interplanetary magnetic field, particularly during the passage of an interplanetary coronal mass ejection (ICME), is a crucial objective for space weather predictions. Currently, only a handful…
The extra-solar planet HD209458b has been found to have an extended atmosphere of escaping atomic hydrogen (Vidal-Madjar et al. 2003), suggesting that ``hot Jupiters'' closer to their parent stars could evaporate. Here we estimate the…