Related papers: New self-consistent wind parameters fitting optica…
Mass loss governs the evolution of massive stars and shapes the stellar surroundings. To quantify the impact of the stellar winds we need to know the exact mass-loss rates; however, empirical constraints on the rates are hampered by limited…
We provide mass-loss rate predictions for O stars from Large and Small Magellanic Clouds. We calculate global (unified, hydrodynamic) model atmospheres of main sequence, giant, and supergiant stars for chemical composition corresponding to…
Stellar winds are an important aspect of our understanding of the evolution of massive stars and their input into the interstellar medium. Here we present solutions for the velocity field and mass-loss rates for stellar outflows as well as…
We pesent models for the velocity structure in the supersonic part of hot star winds in order to estimate the effects of clumping in density and velocity. XSTAR (Kallman,2018) was used to calculate radiation pressure in spectral lines…
Recent studies of O-type stars demonstrated that discrepant mass-loss rates are obtained when different diagnostic methods are employed - fitting the unsaturated UV resonance lines (e.g. P v) gives drastically lower values than obtained…
Reliable predictions of mass-loss rates are important for massive-star evolution computations. We aim to provide predictions for mass-loss rates and wind-momentum rates of O-type stars, carefully studying the behaviour of these winds as…
X-rays give direct evidence of instabilities, time-variable structure, and shock heating in the winds of O stars. The observed broad X-ray emission lines provide information about the kinematics of shock-heated wind plasma, enabling us to…
We present a state-of-the-art analysis technique able to simultaneously reproduce the entire H and He spectra of OB-type stars in the visual and the near-IR and to derive highly accurate metal abundances (so far C and N). The spectrum…
The modified Castor, Abbott, and Klein (m-CAK) theory predicts different wind regimes based on the line force parameter for changes in ionization ($\delta$) and the rotation parameter ($\Omega$). Stationary hydrodynamic studies have…
We present a new method for using measured X-ray emission line fluxes from O stars to determine the shock-heating rate due to instabilities in their radiation-driven winds. The high densities of these winds means that their embedded shocks…
Archival X-ray spectra of the four prominent single, non-magnetic O stars Zeta Pup, Zeta Ori, Ksi Per and Zeta Oph, obtained in high resolution with Chandra HETGS/MEG have been studied. The resolved X-ray emission line profiles provide…
Line-driven wind instability is expected to cause small-scale wind inhomogeneities, X-ray emission, and wind line profile variability. The instability can already develop around the sonic point if it is initiated close to the photosphere…
We present solutions for the velocity field and mass-loss rates for 2D axisymmetric outflows, as well as for the case of mass accretion through the use of the Lambert W-function. For the case of a rotating radiation-driven wind the velocity…
Context. The uncertainty in the degree to which radiation-driven winds of hot stars might be affected by small inhomogeneities in the density leads to a corresponding uncertainty in the determination of the atmospheric mass loss rates from…
Mass-loss rates currently in use for hot, massive stars have recently been seriously questioned, mainly because of the effects of wind clumping. We investigate the impact of clumping on diagnostic ultraviolet resonance and optical…
The rate at which massive stars eject mass in stellar winds significantly influences their evolutionary path. Cosmic rates of nucleosynthesis, explosive stellar phenomena, and compact object genesis depend on this poorly known facet of…
Radiative pressure exerted by line interactions is a prominent driver of outflows in astrophysical systems, being at work in the outflows emerging from hot stars or from the accretion discs of cataclysmic variables, massive young stars and…
Mass-loss rates from hot, massive stars are important for a range of astrophysical applications. We present \href{https://lime.ster.kuleuven.be/}{LIME}, a fast, efficient, and easy-to-use real-time mass-loss calculator for line-driven winds…
New numerical models of line-driven stellar winds of late O stars are presented. Statistical equilibrium (NLTE) equations of the most abundant elements are solved. Properly obtained occupation numbers are used to calculate consistent…
Identifying trends between observational data and the range of physical parameters of massive stars is a critical step to the still-elusive full understanding of the source, structure, and evolution of X-ray emission from the stellar winds,…