Massive stars have strong stellar winds that direct their evolution through the upper
Hertzsprung–Russell diagram and determine the black hole mass function. Furthermore …

Mass loss is a key process in the evolution of massive stars, and must be understood
quantitatively if it is to be successfully included in broader astrophysical applications such as …

Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Their X-ray
spectra have been important in constraining physical processes that heat plasma in stellar …

Context. The mass-loss rate is a key parameter of massive stars. Adequate stellar
atmosphere models are required for spectral analyses and mass-loss determinations …

Massive stars, at least∼ 10 \sim10 times more massive than the Sun, have two key
properties that make them the main drivers of evolution of star clusters, galaxies, and the …

We investigate the degree to which the nearly symmetric form of X-ray emission lines seen
in Chandra spectra of early-type supergiant stars could be explained by the possibly porous …

The origin, geometry, and kinematics of the broad-line region (BLR) gas in quasars and
active galactic nuclei (AGN) are uncertain. We demonstrate that clumpy biconical disc winds …

Archival X-ray spectra of the four prominent single, non-magnetic O stars ζ Pup, ζ Ori, ξ Per
and ζ Oph, obtained in high resolution with Chandra HETGS/MEG have been studied. The …

We calculate global (unified) wind models of main-sequence, giant, and supergiant O stars
from our Galaxy. The models are calculated by solving hydrodynamic, kinetic equilibrium …

The clumping of massive star winds is an established paradigm, which is confirmed by
multiple lines of evidence and is supported by stellar wind theory. The purpose of this paper …