Related papers: Parker's Stellar Wind Model for Polytropic Gas Flo…
Different hydrodynamic regimes for the gaseous outflows generated by multiple supernovae explosions and stellar winds occurring within compact and massive star clusters are discussed. It is shown that there exists the threshold energy that…
Fast magnetosonic waves in a magnetically-dominated plasma are investigated. In the pulsar wind, these waves may transport a significant fraction of the energy flux. It is shown that the nonlinear steepening and subsequent formation of…
Magnetic stresses collimate protostellar winds into a common distribution of force with angle. Sweeping into the ambient medium, such winds drive bipolar molecular outflows whose properties are insensitive to the distribution of ambient gas…
We extend the analytic expressions for polytropic wind-driven bubbles and their shock structures, formulated initially in Koo and McKee 1992(a,b), focusing on spherically symmetric configurations in astrophysical environments with…
Models of exoplanet atmospheres based on Parker-wind density and velocity profiles are a common choice in fitting spectroscopic observations tracing planetary atmospheric escape. Inferring atmospheric properties using these models often…
We review the basic concepts, the present state of theoretical models, and the future prospects for theory and observations of pulsating stellar atmospheres. Our emphasis is on radially pulsating cool stars, which dynamic atmospheres…
The topic of wind-clumping has been the subject of much activity in recent years, due to the impact that it can have on derived mass-loss rates. Here we present an alternative method of investigating wind-clumping, that of polarimetry. We…
As part of the project Pathways to Habitability (http://path.univie.ac.at/), we study the properties of the stellar winds of low-mass and Sun-like stars, and their influences on the atmospheres of potentially habitable planets. For this…
We present two dimensional hydrodynamic calculations of free expanding supergalactic winds, taking into consideration strong radiative cooling. Our main premise is that supergalactic winds are powered by collections of superstar clusters.…
Statistical classification of the Helios solar wind observations into several populations sorted by bulk speed has revealed an outward acceleration of the wind. The faster the wind is, the smaller is this acceleration in the 0.3 - 1 au…
Aims: We develop a method for estimating the properties of stellar winds for low-mass main-sequence stars between masses of 0.4 and 1.1 solar masses at a range of distances from the star. Methods: We use 1D thermal pressure driven…
Interactions between the winds of stars and the magnetospheres and atmospheres of planets involve many processes, including the acceleration of particles, heating of upper atmospheres, and a diverse range of atmospheric loss processes.…
Stars interact with their planets through gravitation, radiation, and magnetic fields. Although magnetic activity decreases with time, reducing associated high-energy (e.g., coronal XUV emission, flares), stellar winds persist throughout…
The structure and evolution of wind-blown bubbles (WBBs) around massive stars has primarily been investigated using an energy-conserving model of wind-blown bubbles. While this model is useful in explaining the general properties of the…
The dynamics of the wind-wind collision in massive stellar binaries is investigated using three-dimensional hydrodynamical models which incorporate gravity, the driving of the winds, the orbital motion of the stars, and radiative cooling of…
Neutron stars lose the bulk of their rotational energy in the form of a pulsar wind: an ultra-relativistic outflow of predominantly electrons and positrons. This pulsar wind significantly impacts the environment and possible binary…
The connection between turbulence and solar-wind acceleration, long known in space physics, is further developed in this Letter by establishing a robust empirical law that relates the bulk-flow speed to the magnetohydrodynamic-scale…
We focus on the thermodynamic behavior of Polytropic gas as a candidate for dark energy. We use the general arguments of thermodynamics to investigate its properties and behavior. We find that a Polytropic gas may exhibit the dark energy…
We perform numerical simulations to investigate the stellar wind from interacting binary stars. Our aim is to find analytical formulae describing the outflow structure. In each binary system the more massive star is in the asymptotic giant…
Stochastic acceleration of particles under a pressure balance condition can accommodate the universal $p^{-5}$ spectra observed under many different conditions in the inner heliosphere. In this model, in order to avoid an infinite build up…