Related papers: A New Superwind Wolf-Rayet Galaxy Mrk 1259
(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…
We report the discovery of 5 massive Wolf-Rayet (WR) stars resulting from a programme of follow-up spectroscopy of candidate emission line stars in the AAO/UKST Southern Galactic Plane H-alpha survey. The 6195-6775 angstrom spectra of the…
We report the discovery of a new Wolf-Rayet star in the direction of Cygnus. The star is strongly reddened but quite bright in the infrared, with J = 9.22, H = 8.08 and K = 7.09 (2MASS). On the basis of its H + K spectrum, we have…
Observed properties of Wolf-Rayet stars at high metallicity are reviewed. Wolf-Rayet stars are more common at higher metallicity, as a result of stronger mass-loss during earlier evolutionary phases with late WC subtypes signatures of solar…
Long gamma-ray bursts are thought to be caused by a subset of exploding Wolf-Rayet stars. We argue that the circumstellar absorption lines in early supernova and in gamma-ray burst afterglow spectra may allow us to determine the main…
We construct revised near-infrared absolute magnitude calibrations for 126 Galactic Wolf-Rayet (WR) stars at known distances, based in part upon recent large scale spectroscopic surveys. Application to 246 WR stars located in the field,…
Recently, a soft black-body component was observed in the early X-ray afterglow of GRB 060218, which was interpreted as shock breakout from the thick wind of the progenitor Wolf-Rayet (WR) star of the underlying Type Ic SN 2006aj. In this…
Galactic winds are essential to regulation of star formation in galaxies. To study the distribution and dynamics of molecular gas in a wind, we imaged the nearby starburst galaxy NGC 1482 in CO ($J=1\rightarrow0$) at a resolution of 1''…
Wolf-Rayet (WR) 140 is the archetypal periodic dust-forming colliding-wind binary that hosts a carbon-rich WR (WC) star and an O-star companion with an orbital period of 7.93 years and an orbital eccentricity of 0.9. Throughout the past…
New high resolution interferometer data of 10 IR ultraluminous galaxies shows the molecular gas is in rotating nuclear rings or disks with radii 300 to 800 pc. Most of the CO flux comes from a moderate-density, warm, intercloud medium…
Long gamma-ray bursts involve the most powerful cosmic explosions since the Big Bang. Whilst it has been established that GRBs are related to the death throes of massive stars, the identification of their progenitors has proved challenging.…
Spectroscopic observations have shown for decades that the Wolf-Rayet (WR) phenomenon is ubiquitous among stars with different initial masses. Although much effort to understand the winds from massive WR stars has been presented in the…
We measure transverse proper motion velocities of LMC Wolf-Rayet (WR) stars using Gaia DR3 astrometry. The combined velocity distribution of WNh, O If*/WN, and WNL very massive stars ($>100\ M_\odot$; VMS) shows both slow, unejected objects…
We present narrowband H$\alpha$ imaging of nearby Wolf-Rayet (WR) galaxies known as a subset of starburst galaxies. The H$\alpha$ images have been used to show morphology of star-forming regions in galaxies, which leads to speculate that…
As part of a search for Wolf-Rayet (WR) stars in the Magellanic Clouds, we have discovered a new type of WR star in the Large Magellanic Cloud (LMC). These stars have both strong emission lines, as well as He ii and Balmer absorption lines…
We analyse $\textit{XMM-Newton}$ RGS spectra of Wolf-Rayet (WR) 140, an archetype long-period eccentric WR+O colliding wind binary. We evaluate the spectra of O and Fe emission lines and find that the plasmas emitting these lines have the…
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…
We present the discovery of extreme nitrogen enrichment by Wolf Rayet nitrogen stars (WN) in the metal-poor (~10% Z_odot), lensed, compact (R_eff ~ 20 pc) galaxy RXCJ2248 at z=6.1, revealed by unprecedentedly deep JWST/NIRSpec…
Examination of the temporal variability properties of several strong optical recombination lines in a large sample of Galactic Wolf-Rayet (WR) stars reveals possible trends, especially in the more homogeneous WC than the diverse WN…
We investigate the stellar and nebular properties of 9 H II regions in the spiral galaxy M101 with far-ultraviolet (FUV; ~900-2000 \r{A}) and optical (~3200-10000 \r{A}) spectra. We detect significant C III] 1907,1909 nebular emission in 7…