Related papers: Finding Wolf-Rayet Stars in the Local Group
(shortened) We investigate the properties of Galactic WR stars and their environment to identify evolutionary channels that may lead to the formation of LGRBs. To this purpose we compile available information on the spectropolarimetric…
We recall the basic physical principles governing the evolution of stars with some emphasis on the role played by the nuclear reactions. We argue that in general it is not possible from observations of stars to deduce constraints on the…
Wolf-Rayet stars are the evolved descendents of massive stars. Their extraordinary properties make them useful tracers of the stellar initial mass function (IMF) in a young stellar population. I discuss how the interpretation of spectral…
We have surveyed the metal-rich spiral galaxy M83 (NGC5236) for its Wolf-Rayet population using VLT-FORS2 narrow-band imaging and follow-up spectroscopy. From a total of 280 candidates identified using HeII 4686 imaging, Multi Object…
The Magellanic Clouds are close enough to the Milky Way to provide an excellent environment in which to study extragalactic PNe. Most of these PNe are bright enough to be spectroscopically observed and spatially resolved. With the latest…
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…
[Abridged] [...] AIMS: We aim to establish the stellar parameters and mass-loss rates of the Galactic WC stars. These data provide the empirical basis of studies of (i) the role of WC stars in the evolution of massive stars, (ii) the…
(Abridged) We have performed a comprehensive analysis of a sample of 20 starburst galaxies, most of them classified as Wolf-Rayet galaxies. In this paper, the last of the series, we analyze the global properties of our galaxy sample using…
We construct a speculative scenario for the evolution of Wolf-Rayet central stars of planetary nebula. It is clear from the latest infra-red observations that a new perspective has to be adopted: the simultaneous presence of carbon- and…
Galaxies in the Local Group span a factor of 15 in metallicity, ranging from the super-solar M31 to the Wolf-Lundmark-Melotte (WLM) galaxy, which is the lowest-metallicity (0.1xZsun) Local Group galaxy currently forming stars. Studies of…
Wolf-Rayet (WR) stars are massive ($\geq$10 M$_{\odot}$) evolved stars undergoing advanced nuclear burning in their cores, rapidly approaching the end of their lives as supernovae. Their powerful winds enrich the interstellar medium with…
Massive stars are the engines of the Cosmos, shaping their environments and driving galaxy evolution across cosmic time. Yet, this general textbook picture faces many challenges when trying to turn abstract insights into quantitative…
M101 is an ideal target in which to test predictions of massive star birth and evolution. The large abundance gradient across M101 (a factor of 20) suggests that many more WR stars must be found in the inner parts of this galaxy than in the…
We report the results of a survey of radio continuum emission of Galactic Wolf-Rayet stars north of declination -46 degrees. The observations were obtained at 8.46 GHz (3.6cm) using the Very Large Array (VLA), with an angular resolution of…
We present follow-up spectroscopy of emission line candidates detected on near-infrared narrow band images in the inner Galaxy (Homeier et al. 2003). The filters are optimized for the detection of Wolf-Rayet stars and other objects which…
Recent large scale Galactic Plane H$\alpha$ surveys allow a re-examination of the environs of Wolf-Rayet (WR) stars for the presence of a circumstellar nebula. Using the morphologies of WR nebulae known to be composed of stellar ejecta as a…
We have analysed, for the first time, the clustering properties of Wolf-Rayet (W-R) galaxies, using a large sample of 846 W-R galaxies selected from the Data Release 4 (DR4) of the SDSS. We compute the cross-correlation function between W-R…
We have investigated and applied machine-learning algorithms for Infrared Colour Selection of Galactic Wolf-Rayet (WR) candidates. Objects taken from the GLIMPSE catalogue of the infrared objects in the Galactic plane can be classified into…
We present the final results of an imaging and spectroscopic search for stars in the Large Magellanic Cloud (LMC) with C II 7231, 7236 emission lines. The goal is to identify and study [WC11] stars, the coolest of the low-mass Wolf-Rayet…
The Magellanic Clouds are nearby dwarf irregular galaxies that represent a unique laboratory for studying galaxy interactions. Their morphology and dynamics have been heavily influenced by their mutual interactions as well as with their…