Related papers: Gamma-rays from Wolf-Rayet stellar winds
We present the results of population syntheses for binary stars carried out using the ``Scenario Machine'' code with the aim of analyzing events that may result in long gamma-ray bursts. We show that the observed distribution of…
The X-ray properties of twenty ~1 Myr old O, B, and A stars of the Orion Trapezium are examined with data from the Chandra Orion Ultradeep Project (COUP). On the basis of simple theories for X-ray emission, we define two classes separated…
The migration of profile sub-peaks identified in time-monitored optical emission lines of Wolf-Rayet star spectra provides a direct diagnostic of the dynamics of their stellar winds via a measured line-of-sight velocity change per unit…
The association of a supernova with a gamma-ray burst (GRB 030329) implies a massive star progenitor, which is expected to have an environment formed by pre-burst stellar winds. Although some sources are consistent with the expected wind…
The mass loss from Wolf-Rayet (WR) stars is of fundamental importance for the final fate of massive stars and their chemical yields. Its Z-dependence is discussed in relation to the formation of long-duration Gamma Ray Bursts (GRBs) and the…
Massive Star Clusters (SCs) have been proposed as important CR sources, with the potential of explaining the high-energy end of the Galactic cosmic-ray (CR) spectrum, that Supernova Remnants (SNRs) seem unable to account for. Thanks to fast…
The polarimetric and photometric variability of Wolf-Rayet (WR) stars as caused by clumps in the winds, is revisited. In the model which is improved from Li et al. 2000, the radial expansion of the thickness is accounted for, but we retain…
We compute the thermal X-ray emission from hydrodynamic simulations of the 30 Wolf-Rayet (WR) stars orbiting within a parsec of Sgr A$^*$, with the aim of interpreting the Chandra X-ray observations of this region. The model well reproduces…
Determining the Galactic distribution and numbers of massive stars, such as Wolf-Rayet stars (WRs), is hampered by intervening Galactic or local circumstellar dust obscuration. In order to probe such regions of the Galaxy we can use…
Wolf-Rayet stars (WRs) are one of the final evolutionary stages of massive stars and immediate progenitors of stellar-mass black holes. Their multiplicity forms an important anchor point in single and binary population models for predicting…
Wolf-Rayet (WR) stars are the evolved descendants of massive O-type stars and are considered to be progenitor candidates for Type Ib/c core-collapse supernovae (SNe). Recent results of our HST/WFC3 survey of Wolf-Rayet stars in M101 are…
Context: The recent detection of very high-energy (VHE) gamma-ray emission from the direction of the W43 star-forming region prompted us to investigate its stellar population in detail in an attempt to see wether or not it is possible an…
We use integral field spectroscopy to study in detail the Wolf-Rayet (WR) population in NGC 3310, spatially resolving 18 star-forming knots with typical sizes of 200-300 pc in the disc of the galaxy hosting a substantial population of WRs.…
(Abridged) We have performed a comprehensive multiwavelength analysis of a sample of 20 starburst galaxies that show the presence of a substantial population of massive stars. The main aims are the study of the massive star formation and…
We report precision ground-based broadband optical intensity and linear-polarisation light-curves for the sky's brightest WN8 star, WR40. WN8 stars are notorious for their high level of variability, stemming from stochastic clumps in their…
Binary systems formed by early-type stars with strong winds are known to display variable non-thermal radio emission, thermal X-rays, and, at least in one case (Eta Carina), $\gamma$ rays. Some of these systems are quite eccentric and the…
In this paper, high quality spectropolarimetric observations of the Wolf-Rayet (WR) Star WR1 (HD4004) obtained with ESPaDOnS at CFHT are presented. All major emission lines present in the spectrum show depolarization in the relative Stokes…
Wolf-Rayet (WR) stars, as they are advanced stages of the life of massive stars, provide a good test for various physical processes involved in the modelling of massive stars, such as rotation and mass loss. In this paper, we show the…
The H.E.S.S. collaboration recently reported the discovery of VHE gamma-ray emission coincident with the young stellar cluster Westerlund 2. This system is known to host a population of hot, massive stars, and, most particularly, the WR…
Colliding-wind binaries (CWBs) constitute an emerging class of $\gamma$-ray sources powered by strong, dense winds in massive stellar systems. The most powerful of them are those binaries hosting a Wolf-Rayet (WR) star. Following the recent…