Related papers: Massive Stars in the Arches Cluster
Context: The ESO Public Survey "VISTA Variables in the V\'ia L\'actea" (VVV) provides deep multi-epoch infrared observations for an unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. In this survey nearly…
We report the discovery of additional hot and massive stars in the cluster surrounding the soft gamma repeater SGR 1806-20, based upon UKIRT and Keck near-infrared spectroscopy. Of the newly identified stars, three are Wolf-Rayet stars of…
This study is the second part of a survey searching for large-scale spectroscopic variability in apparently single Wolf-Rayet (WR) stars. In a previous paper (Paper I), we described and characterized the spectroscopic variability level of…
The WN3/O3 Wolf-Rayet (WR) stars were discovered as part of our survey for WRs in the Magellanic Clouds. The WN3/O3s show the emission lines of a high-excitation WN star and the absorption lines of a hot O-type star, but our prior work has…
We report new results from our effort to identify obscured Wolf-Rayet stars in the Galaxy. Candidates were selected by their near-infrared (2MASS) and mid-infrared (Spitzer/GLIMPSE) color excesses, which are consistent with free-free…
Surveys of Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) have yielded a fairly complete catalog of 154 known stars. We have conducted a comprehensive, multiwavelength study of the interstellar/circumstellar environments of WR…
In recent years, systems involving massive stars with large wind kinetic power have been considered as promising sites for investigating relativistic particle acceleration in low radio frequencies. With this aim, we observed two Wolf-Rayet…
Today, we have a sufficiently complete picture of what the Wolf--Rayet (WR) stars are. Predictions of stellar evolution theory are in a good agreement with their parameters, estimated from observational data using stellar atmospheres codes;…
The discovery of hypervelocity stars (HVS) leaving our galaxy with speeds of nearly $10^{3}$ km s$^{-1}$ has provided strong evidence towards the existence of a massive compact object at the galaxy's center. HVS ejected via the disruption…
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…
At a projected distance of ~26 pc from Sgr A*, the Arches cluster provides insight to star formation in the extreme Galactic Center (GC) environment. Despite its importance, many key properties such as the cluster's internal structure and…
Towards the end of their evolution hot massive stars develop strong stellar winds and appear as emission line stars, such as WR stars or LBVs. The quantitative description of the mass loss in these important pre-SN phases is hampered by…
As deep spectroscopic campaigns extend to higher redshifts and lower stellar masses, the interpretation of galaxy spectra depends increasingly upon models for very young stellar populations. Here we present new HST/COS ultraviolet…
We present high-angular-resolution radio continuum observations of the Quintuplet cluster, one of the most emblematic massive clusters in the Galactic centre. Data were acquired in two epochs and at 6 and 10 GHz with the Karl J. Jansky Very…
We report the first-ever discovery of an extragalactic Wolf-Rayet (WR)star with Spitzer. A new WR star in the Large Magellanic Cloud (LMC) was revealed via detection of its circumstellar shell using 24 {\mu}m images obtained in the…
We study the stellar and wind properties of massive stars in the central cluster of the Galaxy. We use non-LTE atmosphere models including winds and line-blanketing to fit their H and K band spectra obtained with the 3D spectrograph SINFONI…
Nuclear star clusters (NSCs) are located at the photometric and dynamical centers of the majority of galaxies. They are among the densest star clusters in the Universe. The NSC in the Milky Way is the only object of this class that can be…
The Galactic center (GC) provides a unique laboratory for a detailed examination of the interplay between massive star formation and the nuclear environment of our Galaxy. Here, we present an 100 ks Chandra ACIS observation of the Arches…
(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: Comprehensive studies of Wolf-Rayet stars were performed in the past for the Galactic and the LMC population. The results revealed significant differences, but also unexpected similarities between the WR populations of these…