Related papers: The metallicity dependence of WR winds
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…
Aims: Following our comprehensive studies of the WR stars in the Milky Way, we now present spectroscopic analyses of almost all known WN stars in the LMC. Methods: For the quantitative analysis of the wind-dominated emission-line spectra,…
(Abridged) We perform a comprehensive multiwavelength analysis of a sample of 20 starburst galaxies that show the presence of a substantial population of Wolf-Rayet (WR) stars. In this paper we present the analysis of the O and WR star…
CONTEXT: Very massive stars pass through the Wolf-Rayet (WR) stage before they finally explode. Details of their evolution have not yet been safely established, and their physics are not well understood. Their spectral analysis requires…
We discuss recent models on the evolution of massive stars at very low metallicity including the effects of rotation, magnetic fields and binarity. Very metal poor stars lose very little mass and angular momentum during the main sequence…
Massive stars are "cosmic engines" (cf the title of the IAU Symposium 250). They drive the photometric and chemical evolution of galaxies, inject energy and momentum through stellar winds and supernova explosions, they modify in this way…
A growing number of Galactic Wolf-Rayet (WR) stars, in particular WC and transitional WN/C (WNC) objects, have been reported at comparatively low luminosities. If confirmed, these low-luminosity WR stars provide stringent tests of…
Massive stars played a key role in the early evolution of the Universe. They formed with the first halos and started the re-ionisation. It is therefore very important to understand their evolution. In this review, we first recall the effect…
Hydrogen-deficient Wolf-Rayet (WR) stars are potential candidates of Type Ib/Ic supernova (SN Ib/Ic) progenitors and their evolution is governed by mass loss. Stellar evolution models with the most popular prescription for WR mass-loss…
Most stars will experience episodes of substantial mass loss at some point in their lives. For very massive stars, mass loss dominates their evolution, although the mass loss rates are not known exactly, particularly once the star has left…
The majority of Wolf-Rayet (WR) stars represent the stripped cores of evolved massive stars who lost most of their hydrogen envelope. In low metallicity environments, such as the Small Magellanic Cloud (SMC), stellar winds are weaker and…
Radiation-driven winds heavily influence the evolution and fate of massive stars. Feedback processes from these winds impact the properties of the interstellar medium of their host galaxies. The dependence of mass loss on stellar properties…
We investigate Wolf-Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal…
The properties, impact, and fate of hot stars cannot be understood without considering their winds. Revealed to be an almost ubiquitous phenomenon in the regime of massive stars, the winds of hot stars arise from a complex physical…
Wolf-Rayet stars (WRs) are evolved massive stars, and the relative number of WC-type and WN-type WRs should vary with metallicity, providing a sensitive test of stellar evolutionary theory. The observed WC/WN ratio is much higher than that…
(abridged) We propose the new designation ``WNH'' for luminous Wolf-Rayet (WR) stars of the nitrogen sequence with H in their spectra. These are commonly called WNL stars (e.g., WN7h), but this new shorthand avoids confusion because there…
One of the key questions in Astrophysics concerns the issue of whether there exists an upper-mass limit to stars, and if so, what physical mechanism sets this limit, which might also determine if the upper-mass limit is metallicity (Z)…
The fast, dense winds which characterize Wolf-Rayet (WR) stars obscure their underlying cores, and complicate the verification of evolving core and nucleosynthesis models. Core evolution can be probed by measuring abundances of wind-borne…
Wolf-Rayet (WR) stars near solar metallicity are believed to be driven by radiation pressure on the UV spectral lines of metal ions. As the metallicity decreases so does the line opacity, therefore the mass-loss rate. However, since the…
We have run direct N-body simulations to investigate the impact of stellar evolution and dynamics on the structural properties of young massive (3x10^4 solar masses) star clusters (SCs) with different metallicities (Z=1, 0.1, 0.01 solar…