Related papers: A Multiwavelength Study of Evolved Massive Stars i…

Wolf-Rayet (WR) stars are evolved massive stars with strong fast stellar winds. WR stars in our Galaxy have shown three possible sources of X-ray emission associated with their winds: shocks in the winds, colliding stellar winds, and…

Elemental abundances hold important information about the star formation history in the Galactic Center. The thermal X-ray spectra of certain stars can provide a robust probe of elemental abundances, mainly through the presence of K-shell…

We present and use new spectra and narrow-band images, along with previously published broad-band images, of stars in the Arches cluster to extract photometry, astrometry, equivalent width, and velocity information. The data are interpreted…

Photometry at 3.4 and 4.6 micron of 128 Population~I WC type Wolf-Rayet stars in the Galaxy and 12 in the Large Magellanic Cloud (LMC) observed in the WISE NEOWISE-R survey was searched for evidence of circumstellar dust emission and its…

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…

Young massive (M >10^4 Msun) stellar clusters are a good laboratory to study the evolution of massive stars. Only a dozen of such clusters are known in the Galaxy. Here we report about a new young massive stellar cluster in the Milky Way.…

Rich in HII regions, giant molecular clouds are natural laboratories to study massive stars and sequential star formation. The Galactic star forming complex W33 is located at l=~12.8deg and at a distance of 2.4 kpc, has a size of ~10 pc and…

Based on $K$-band integral-field spectroscopy, we analyze four Wolf-Rayet stars of the nitrogen sequence (WN) found in the inner part of the Quintuplet cluster. All WN stars (WR102d, WR102i, WR102hb, and WR102ea) are of spectral subtype…

We review the properties of massive star evolution in different environments, where the major environmental factor is metallicity. Comparisons between evolutionary models and observations of massive OB, WR stars and related objects are…

We have selected galaxies with very high levels of H$\alpha$ emission (EQW(H$\alpha$)$>$700 \AA.) in their central regions from the final data release of the MaNGA survey . Our study focuses on 14 very well-resolved nearby galaxies with…

(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…

This paper discusses our ongoing efforts to characterize dust-enshrouded Wolf-Rayet (WR) stars in the radio and infrared. We have used the Very Large Array to measure the broadband radio spectrum of WR stars in suspected binary systems and…

We present refined color-color selection criteria for identifying Wolf-Rayet (WR) stars using available mid infrared (MIR) photometry from WISE in combination with near infrared (NIR) photometry from 2MASS. Using a sample of spectrally…

We present a multi-wavelength study of embedded massive clusters in the nearby (3.9 Mpc) starburst galaxy NGC 4449 in an effort to uncover the earliest phases of massive cluster evolution. By combining high resolution imaging from the radio…

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…

Aims. Young, massive stars have been found at projected distances R < 0.5 pc from supermassive black hole, Sgr A* at the center of our Galay. In recent years, increasing evidence has been found for the presence of young, massive stars also…

Located within the central region of the Galaxy, the Arches cluster appears to be one of the youngest, densest and most massive stellar aggregates within the Milky Way. As such it has the potential to be a uniquely instructive laboratory…

Current mass-loss rate estimates imply that main sequence winds are not sufficient to strip away the H-rich envelope to yield Wolf-Rayet (WR) stars. The rich transitional population of Westerlund 1 (Wd 1) provides an ideal laboratory to…

The Galactic center Arches stellar cluster, detected and studied until now only in the near-infrared, is comprised of at least one hundred massive (M>20 Msun) stars. Here we report the detection at centimeter wavelengths of radio continuum…

The central parsec around the super-massive black hole in the Galactic Center hosts more than 100 young and massive stars. Outside the central cusp (R~1") the majority of these O and Wolf-Rayet (WR) stars reside in a main clockwise system,…