Related papers: Modeling Ultraviolet Wind Line Variability in Mass…
We calculate the flux received from a binary system obscured by a circumbinary disc. The disc is modelled using two dimensional hydrodynamical simulations, and the vertical structure is derived by assuming it is isothermal. The…
Dwarf carbon (dC) stars, main sequence stars showing carbon molecular bands, are enriched by mass transfer from a previous asymptotic-giant-branch (AGB) companion, which has since evolved to a white dwarf. While previous studies have found…
Recent large-scale spectropolarimetric surveys have established that a small but significant percentage of massive stars host stable, surface dipolar magnetic fields with strengths on the order of kG. These fields channel the dense,…
In this paper, high quality spectropolarimetric observations of the Wolf-Rayet (WR) Star WR1 (HD4004) obtained with ESPaDOnS at CFHT are presented. All major emission lines present in the spectrum show depolarization in the relative Stokes…
We present new spectra of WR 140 (HD 193793) in the JHK bands with some covering the 1.083-micron He I emission line at higher resolution, observed between 2000 October and 2003 May to cover its 2001 periastron passage. The WC7 + O4-5…
Mass loss from massive stars plays a determining role in their evolution through the upper Hertzsprung-Russell diagram. The hydrodynamic theory that describes their steady-state winds is the line-driven wind theory (m-CAK). From this…
Context. B hypergiants (BHGs) are important for understanding high-mass stellar evolution. While they are in a similar parameter space of B supergiants (BSGs), some BHGs are known to be luminous blue variables (LBVs). Their spectra with…
Radio observations are an effective tool to discover particle acceleration regions in colliding-wind binaries, through detection of synchrotron radiation; these regions are natural laboratories for the study of relativistic particles.…
We present results from combining a grid-based radiative transfer code with a Smoothed Particle Hydrodynamics code to produce a flexible system for modelling radiation hydrodynamics. We use a benchmark model of a circumstellar disc to…
High-dispersion IUE data encode significant information about aggregate line absorptions that cannot be conveniently extracted from individual spectra. We apply a new technique in which fluxes from each echelle order of a short wavelength…
Radiation-driven winds are ubiquitous in massive stars, but in Very Massive Stars (VMSs), mass loss dominates their evolution, chemical yields, and ultimate fate. Theoretical predictions have often relied on extrapolations of O star…
Classical Wolf Rayet (WR) stars are direct supernova progenitors undergoing vigorous mass-loss. Understanding the dense and fast outflows of such WR stars is thus crucial for understanding advanced stages of stellar evolution, the dynamical…
RY Tau is a rapidly rotating Classical T Tauri star observed close to edge-on. The combination of new HST/STIS observations obtained in 2001 with HST/GHRS Archive data from 1993 has allowed us to get, for the first time, information on the…
We present NAOMI/OASIS adaptive-optics assisted integral-field spectroscopy of the transitional massive hypergiant IRC +10420, an extreme mass-losing star apparently in the process of evolving from a Red Supergiant toward the Wolf-Rayet…
A puzzling variety of superorbital modulations have been discovered in several supergiant High-Mass X-ray binaries (sgHMXBs). To investigate the mechanisms driving these superorbital modulations, we have analyzed long-term Neil Gehrels…
A small fraction of the radiative flux emitted by hot stars is absorbed by their winds and redistributed towards longer wavelengths. This effect, which leads also to the heating of the stellar photosphere, is termed wind blanketing. For…
A review of spectroscopic results obtained from Chandra High Energy Transmission Grating Spectrometer and XMM-Newton Reflection Grating Spectrometer observations of several wind-fed high-mass X-ray binaries (HMXBs) is presented. These…
Radiative transfer modelling offers a powerful tool for understanding the enigmatic hydrogen emission lines from T Tauri stars. This work compares optical and near-IR spectroscopy of 29 T Tauri stars with our grid of synthetic line…
We use ultraviolet space-based (FUSE, HST) and optical/IR ground-based (2.3m MSSSO, NTT) spectroscopy to determine the physical parameters of six WC4-type Wolf-Rayet stars in the Large Magellanic Cloud. Stellar parameters are revised…
The wind interaction with the dusty environment of the classical T Tauri star RY Tau has been investigated. During two seasons of 2013-2015 we carried out a spectroscopic and photometric (BVR) monitoring of the star. A correlation between…