Related papers: Galactic cosmic rays on extrasolar Earth-like plan…
We compute the ozone distribution for a model terrestrial paleoatmosphere in which the present oxygen abundance is largely replaced by carbon dioxide, which we argue is a reasonable working assumption. In principle, the presence of carbon…
Using 3D radiative MHD simulations and Lyman-$\alpha$ transit calculations, we investigate the effect of magnetic fields on the observational signatures of atmospheric escape in exoplanets. Using the same stellar wind, we vary the planet's…
The strongly diverging magnetic field lines in the very inner heliosphere, through the associated magnetic focusing/mirroring forces, can, potentially, lead to highly anisotropic galactic cosmic ray distributions close to the Sun. Using a…
The role of cosmic rays generated by supernovae and young stars has very recently begun to receive significant attention in studies of galaxy formation and evolution due to the realization that cosmic rays can efficiently accelerate…
We consider the possibility that cosmic magnetic field, instead of being uniformly distributed, is strongly correlated with the large scale structure of the universe. Then, the observed rotational measure of extra-galactic radio sources…
Radio, X-ray and infrared observations of the inner few hundred pc of the Galactic center have highlighted two characteristics to the ISM. The cosmic ray ionization rate derived from molecular ions such as H$^+_3$, is at least two to three…
The next step on the path toward another Earth is to find atmospheres similar to those of Earth and Venus - high-molecular-weight (secondary) atmospheres - on rocky exoplanets. Many rocky exoplanets are born with thick (> 10 kbar)…
Cosmic Rays escaping the Galaxy exert a force on the interstellar medium directed away from the Galactic disk. If this force is larger than the gravitational pull due to the mass embedded in the Galaxy, then galactic winds may be launched.…
Photochemical hazes are important opacity sources in temperate exoplanet atmospheres, hindering current observations from characterizing exoplanet atmospheric compositions. The haziness of an atmosphere is determined by the balance between…
The photoionization-driven evaporation of planetary atmospheres has emerged as a potentially fundamental process for planets on short period orbits. While 1-D studies have proven the effectiveness of stellar fluxes at altering the…
The intrinsic magnetic fields of exoplanets affect the structure of their atmospheres and plasmaspheres and, therefore, the observational manifestations of transit absorptions. This work proposes a new method for constraining the presence…
A primary goal of characterizing exoplanet atmospheres is to constrain planetary bulk properties, such as their metallicity, C/O ratio, and intrinsic heat. However, there are significant uncertainties in many aspects of atmospheric physics,…
We investigate the effect of the magnetic fields of M dwarf (dM) stars on potentially habitable Earth-like planets. These fields can reduce the size of planetary magnetospheres to such an extent that a significant fraction of the planet's…
Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in…
Both stars and planets can lose mass through an expansive wind outflow, often constrained or channeled by magnetic fields that form a surrounding magnetosphere. The very strong winds of massive stars are understood to be driven by…
While it may seem counterintuitive that X-ray astronomy should give any insights into low-temperature planetary systems, planets orbit stars whose magnetized surfaces divert a small fraction of the stellar energy into high energy products:…
The climate of a terrestrial exoplanet is controlled by the type of host star, the orbital configuration and the characteristics of the atmosphere and the surface. Many rocky exoplanets have higher eccentricities than those in the Solar…
Kepler observations have uncovered the existence of a large number of close-in exoplanets and serendipitously of stellar superflares with emissions several orders of magnitude higher than those observed on the Sun. The interaction between…
Extrasolar planets appear in a chemical diversity unseen in our own solar system. Despite their atmospheres being cold, continuous and transient plasma processes do affect these atmosphere where clouds form with great efficiency. Clouds can…
In this paper, we analyze a new possible biological surface feature for habitable worlds orbiting other stars: biofluorescence. High ultraviolet (UV) and blue radiation fluxes drive the strongest biofluorescence in terrestrial fluorescent…