Related papers: A Search for Wolf-Rayet Stars in the Small Magella…

We present a catalogue of non-nuclear regions containing Wolf-Rayet stars in the metal-rich spiral galaxy M83 (NGC5236). From a total of 283 candidate regions identified using HeII 4686 imaging with VLT-FORS2, Multi Object Spectroscopy of…

The mass-loss rates of hot, massive, luminous stars are considered a decisive parameter in shaping the evolutionary tracks of such stars and influencing the interstellar medium on galactic scales. The small-scale structures (clumps)…

We present the detection of He II sources in the Im galaxy NGC 1569 from HST WFPC2 imagery. Out of the fifteen detections, seven were Wolf-Rayet stars, five were stellar clusters with associated He II emission, and three were sources of…

An overview of the known Wolf-Rayet (WR) population of the Milky Way is presented, including a brief overview of historical catalogues and recent advances based on infrared photometric and spectroscopic observations resulting in the current…

IC10 is the nearest starburst galaxy, as revealed both by its Halpha surface brightness and the large number of Wolf-Rayet stars (WRs) per unit area. The relative number of known WC- to WN-type WRs has been thought to be unusually high…

We analysed Washington $CMT_1$ photometry of star clusters located along the minor axis of the LMC, from the LMC optical centre up to $\sim$ 39 degrees outwards to the North-West. The data base was exploited in order to search for new star…

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…

We analyse deep images from the VISTA survey of the Magellanic Clouds in the YJKs filters, covering 14 sqrdeg (10 tiles), split into 120 subregions, and comprising the main body and Wing of the Small Magellanic Cloud (SMC). We apply a…

The Small Magellanic Cloud (SMC) hosts a large number of Be/X-ray binaries, however no Be/white dwarf system is known so far, although population synthesis calculations predict that they might be more frequent than Be/neutron star systems.…

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…

We present spectroscopic observations of the central star clusters in NGC 5253 the aim of which is to search for WC stars. Our observations show the presence of Wolf-Rayet (WR) stars not only of WN but also of WC subtype in two star forming…

We present a deep imaging and spectroscopic survey of the Local Group irregular galaxy IC10 using Gemini North and GMOS to unveil its global Wolf-Rayet (WR) population. We obtain a star formation rate (SFR) of 0.045 +/- 0.023 Msun/yr, for…

We present Washington system colour-magnitude diagrams (CMDs) for 17 practically unstudied star clusters located in the bar as well as in the inner disc and outer regions of the Large Magellanic Cloud (LMC). Cluster sizes were estimated…

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…

We made 22 observations on the Small Magellanic Cloud (SMC) and covered full regions by the end of the ASCA mission. We detected 106 discrete sources with a criterion of S/N > 5 and performed systematic analyses on all of the sources. We…

Wolf-Rayet stars have been identified as objects in their final phase of massive star evolution. It has been suggested that Wolf-Rayet stars are the progenitors of long-duration gamma ray bursts in low metallicity environments. However,…

The Magellanic System (MS) encompasses the nearest neighbors of the Milky Way, the Large (LMC) and Small (SMC) Magellanic Clouds, and the Magellanic Bridge (MBR). This system contains a diverse sample of star clusters. Their parameters,…

The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, due to the extreme physical conditions within their line and continuum forming regions. Recently, model atmosphere studies have…

We report the detection of WC stars in 5 Wolf-Rayet (WR) galaxies: He 2-10, NGC 3049, NGC 3125, NGC 5253 and Tol 89. The faint broad CIV5808 line requires sufficiently high S/N to be detected explaining the non-detection of this WC feature…

Aims. We have gathered optical spectra of 8 long-duration GRB host galaxies selected from the archival data of VLT/FORS2. We investigated whether or not Wolf-Rayet (WR) stars can be detected in these GRB host galaxies. We also tried to…