Related papers: Finding Wolf-Rayet Stars in the Local Group
We have carried out a search for Wolf-Rayet galaxies in all galaxies with EW(Hb)>2AA in the SDSS DR6. We identify Wolf-Rayet features using a mixture of automatic and visual classification and find a total of 570 galaxies with significant…
We provide line luminosities and spectroscopic templates of prominent optical emission lines of 133 Galactic Wolf-Rayet stars by exploiting Gaia DR3 parallaxes and optical spectrophotometry, and provide comparisons with 112 counterparts in…
In these latest years, the detection of Wolf-Rayet (WR) stars in Giant HII Regions (GHRs) has yielded several questions about our current understanding of massive stars evolution and hot expanding atmospheres, the age of the ionizing…
In this contribution I present the main research activities of the IAC ``Stellar Populations in Galaxies'' research Group, with emphasis on the subtopics directly related with the study of the evolution of nearby galaxies. In particular, I…
Recent results on the evolution of Local Group dwarf galaxies obtained from VLT imaging and spectroscopy are briefly reviewed, and prospects for dwarf galaxy research at the VLT are discussed in the light of the current and forthcoming…
We present a spectral analysis of four LMC WC-type Wolf-Rayet (WR) stars (BAT99-8, BAT99-9, BAT99-11, and BAT99-52) to shed light on two evolutionary questions surrounding massive stars. The first is: are WO-type WR stars more oxygen…
We present a comprehensive analysis of the photometric variability of (presumably single) nitrogen-rich Wolf-Rayet (WN) stars in the Magellanic Clouds, using long-term observations from the OGLE survey. Our sample comprises 47 stars with no…
We have undertaken a near-IR spectral survey of stars associated with compact nebulae recently revealed by the Spitzer and WISE imaging surveys. These circumstellar nebulae, produced by massive evolved stars, display a variety of symmetries…
Wolf-Rayet (WR) galaxies are a rare population of galaxies that host living high-mass stars during their WR phase (i.e. WR stars) and are thus expected to provide interesting constraints on the stellar Initial Mass Function, massive star…
We have undertaken a near-infrared spectral survey of stars associated with compact mid-IR shells recently revealed by the MIPSGAL (24 micron) and GLIMPSE (8 micron) Spitzer surveys, whose morphologies are typical of circumstellar shells…
We present new low and intermediate-resolution spectroscopic observations of the Wolf Rayet (WR) star population in the massive starburst cluster Westerlund 1. Finding charts are presented for five new WRs - four WNL and one WCL - raising…
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…
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…
One of the challenges for stellar astrophysics is to reach the point at which we can undertake reliable spectral synthesis of unresolved populations in young, star-forming galaxies at high redshift. Here I summarise recent studies of…
The enigmatic oxygen sequence Wolf-Rayet (WO) stars represent a very late stage in massive star evolution, although their exact nature is still under debate. The spectra of most of the WO stars have never been analysed through detailed…
Are WO-type Wolf Rayet (WR) stars in the final stage of massive star evolution before core-collapse? Although WC- and WO-type WRs have very similar spectra, WOs show a much stronger O VI $\lambda \lambda$3811,34 emission-line feature. This…
Massive stars deeply influence their surroundings by their luminosity and the injection of kinetic energy. So far, they have mostly been studied with spatially unresolved observations, although evidence of geometrical complexity of their…
The central region of the Milky Way provides a unique laboratory for a systematic, spatially-resolved population study of evolved massive stars of various types in a relatively high metallicity environment. We have conducted a…
This review aims to give a summary of our understanding of galaxy evolution as infered from studies of nearby galaxies; how observations made with the Hubble Space Telescope have contributed significantly to our detailed understanding of…
(abridged) The strong winds of Wolf-Rayet (WR) stars are important for the mechanical and chemical feedback of the most massive stars and determine whether they end their lives as neutron stars or black holes. In this work we investigate…