Related papers: Finding Wolf-Rayet Stars in the Local Group
We use integral field spectroscopy to study in detail the Wolf-Rayet (WR) population in NGC 3310, spatially resolving 18 star-forming knots with typical sizes of 200-300 pc in the disc of the galaxy hosting a substantial population of WRs.…
Within the Local Universe galaxies can be studied in great detail star by star, and here we review the results of quantitative studies in nearby dwarf galaxies. The Color-Magnitude Diagram synthesis method is well established as the most…
Grids of models of massive stars ($M \ge$ 20 $M_\odot$) with rotation are computed for metallicities $Z$ ranging from that of the Small Magellanic Cloud (SMC) to that of the Galactic Centre. The hydrostatic effects of rotation, the…
We present spectra of 32 previously unpublished confirmed and candidate Wolf-Rayet ([WR]) and weak emission-line (WELS) central stars of planetary nebulae (CSPNe). Eighteen stars have been discovered in the Macquarie/AAO/Strasbourg H-Alpha…
We develop a robust Machine Learning classifier model utilizing the eXtreme-Gradient Boosting (XGB) algorithm for improved classification of Galactic Wolf-Rayet (WR) stars based on Infrared (IR) colors and positional attributes. For our…
Massive evolved stars loss a large fraction of their mass via copious stellar wind or instant outbursts and during certain evolutionary phases they can be identified via the presence of their circumstellar nebulae. In this paper, we present…
Magnetic fields in Wolf-Rayet (WR) stars are not well explored, although there is indirect evidence, e.g. from spectral variability and X-ray emission, that magnetic fields should be present in these stars. Being in an advanced stage of…
The favoured progenitors of long-duration gamma-ray bursts (GRBs) are rapidly rotating Wolf-Rayet (WR) stars. However, most Galactic WR stars are slow rotators, as stellar winds are thought to remove angular momentum. This poses a challenge…
Massive stars are essential to understand a variety of branches of astronomy including galaxy and star cluster evolution, nucleosynthesis and supernovae, pulsars and black holes. It has become evident that massive star evolution is very…
We investigate the influence of Wolf-Rayet (W-R) stars on their surrounding star-forming molecular clouds. We study five regions containing W-R stars in the inner Galactic plane ($l\sim$[14$^\circ$-52$^\circ$]), using multi-wavelength data…
A popular interpretation of recent microlensing studies of the line of sight towards the Large Magellanic Cloud invokes a population of old white dwarf stars in the Galactic halo. Below I review the basic properties of old white dwarf stars…
We present photometry and a preliminary interpretation of a UBVR survey of the Large and Small Magellanic Clouds. We determine improved values for the relative number of blue and red supergiants. We also compare the relative number of Red…
(Abridged) We have performed a comprehensive multiwavelength analysis of a sample of 20 starburst galaxies that show the presence of a substantial population of massive stars. The main aims are the study of the massive star formation and…
We present the main results of the PhD Thesis carried out by L\'opez-S\'anchez (2006), in which a detailed morphological, photometrical and spectroscopical analysis of a sample of 20 Wolf-Rayet (WR) galaxies was realized. The main aims are…
The Ks-band magnitude distribution of carbon-rich and oxygen-rich asymptotic giant branch stars within Local Group galaxies like the Magellanic Clouds, NGC 6822, M33 and SagDIG is easily obtained from ground-based observations. Appropriate…
We present the results of a systematic search for large-scale spectroscopic variability in apparently single Wolf-Rayet stars brighter than ~12.5. In this first paper we characterize the various forms of variability detected and distinguish…
Significant amounts of hydrogen were found in very hot early-type single WN stars in the SMC and the LMC. Recently, we found similar evidence in the Wolf-Rayet star of a short-period LMC binary. We discuss here the relevance of hydrogen for…
Massive stars that become stripped of their hydrogen envelope through binary interaction or winds can be observed either as Wolf-Rayet stars, if they have optically thick winds, or as transparent-wind stripped-envelope stars. We approximate…
We present 22 GHz imaging of regions of massive star formation within the Local Wolf-Rayet Galaxy Sample (LWRGS), a NSF's Karl G. Jansky Very Large Array (VLA) survey of 30 local galaxies showing spectral features of Wolf-Rayet (WR) stars.…
New NTT/SOFI imaging and spectroscopy of the Wolf-Rayet population in Westerlund 1 are presented. Narrow-band near-IR imaging together with follow up spectroscopy reveals four new WR stars, of which three were independently identified…