The fourth catalogue of Population I Wolf-Rayet stars in the Large Magellanic
Cloud

Breysacher, J.; Azzopardi, M.; Testor, G.

doi:10.1051/aas:1999240

Cited by 153 publications

(192 citation statements)

References 72 publications

Supporting

Mentioning

184

Contrasting

Order By: Relevance

“…Indeed, if WN3-5h stars are genuine core-H burning objects, their number should be compared to the number of normal main sequence stars, which is larger than the number of Wolf-Rayet stars. In the LMC, the catalog of Breysacher et al (1999) lists 10 stars with spectral type WN3-5h among 134 objects, corresponding to a fraction of 7% of Wolf-Rayet stars being hydrogen-rich early-type WN objects. Even if a complete census of the Galactic Wolf-Rayet is still missing, it seems that the fraction of WN3-5h is larger in the LMC compared to the Galaxy.…”

Section: Discussionmentioning

confidence: 99%

Evidence of quasi-chemically homogeneous evolution of massive stars up to solar metallicity

Martins

Depagne

Russeil

et al. 2013

A&A

View full text Add to dashboard Cite

Context. Long soft gamma-ray bursts (LGRBs) are usually associated with the death of the most massive stars. A large amount of core angular momentum in the phases preceding the explosion is required to form LGRBs. A very high initial rotational velocity can provide this angular momentum. This velocity strongly influences the way the star evolves: it is mixed in a chemically homogeneous way and evolves directly towards the blue part of the Hertzsprung-Russell (HR) diagram from the main sequence. Aims. We have shown that chemically homogeneous evolution takes place in the Small Magellanic Cloud (SMC) at low metallicity. We want to see whether there is a metallicity threshold above which such an evolution is not possible. Methods. We performed a spectroscopic analysis of H-rich early-type WN stars in the Large Magellanic Cloud (LMC) and the Galaxy. We used the code CMFGEN to determine the fundamental properties (T eff , L) and the surface composition of the target stars. We then placed the stars in the HR diagram and determined their evolution. Results. We show that both the LMC and Galactic WNh stars we selected cannot be explained by standard stellar evolution. They are located on the left of the main sequence but show surface abundances typical of CN equilibrium. In addition, they still contain a large amount of hydrogen. They are thus core-H burning objects. Their properties are consistent with chemically homogeneous evolution. We determine the metallicity of the Galactic stars from their position and Galactic metallicity gradients and conclude that they have 0.6 < Z < 1.0. A moderate coupling between the core and the envelope is required to explain that stellar winds do not extract too much angular momentum to prevent a blueward evolution. Conclusions. We have shown that chemically homogeneous evolution takes place in environments with metallicity up to solar. Since some long gamma-ray bursts appear in (super-)solar environments, such an evolution may be a viable way to form them over a wide range of metallicities.

show abstract

Section: Discussionmentioning

confidence: 99%

Evidence of quasi-chemically homogeneous evolution of massive stars up to solar metallicity

Martins

Depagne

Russeil

et al. 2013

A&A

View full text Add to dashboard Cite

show abstract

“…This catalogue is mostly based on the earlier BAT99 catalogue (Breysacher, Azzopardi & Testor 1999), with some more recent re-classifications. This catalogue contains a total of 94 WN stars.…”

Section: Wr Starsmentioning

confidence: 99%

Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies

Kangas

Portinari

Mattila

et al. 2017

A&A

View full text Add to dashboard Cite

We study the spatial correlations between the H α emission and different types of massive stars in two local galaxies, the Large Magellanic Cloud (LMC) and Messier 33. We compare these to correlations derived for core-collapse supernovae (CCSNe) in the literature to connect CCSNe of different types with the initial masses of their progenitors and to test the validity of progenitor mass estimates which use the pixel statistics method. We obtain samples of evolved massive stars in both galaxies from catalogues with good spatial coverage and/or completeness, and combine them with coordinates of main-sequence stars in the LMC from the SIMBAD database. We calculate the spatial correlation of stars of different classes and spectral types with H α emission. We also investigate the effects of distance, noise and positional errors on the pixel statistics method. A higher correlation with H α emission is found to correspond to a shorter stellar lifespan, and we conclude that the method can be used as an indicator of the ages, and therefore initial masses, of SN progenitors. We find that the spatial distributions of type II-P SNe and red supergiants of appropriate initial mass ( 9 M ) are consistent with each other. We also find the distributions of type Ic SNe and WN stars with initial masses 20 M consistent, while supergiants with initial masses around 15 M are a better match for type IIb and II-L SNe. The type Ib distribution corresponds to the same stellar types as type II-P, which suggests an origin in interacting binaries. On the other hand, we find that luminous blue variable stars show a much stronger correlation with H α emission than do type IIn SNe.

show abstract

“…(1) Breysacher et al (1999); (2) van der Hucht (2001); (3) Blum et al (2001); (4) Negueruela & Clark (2005).…”

Section: Origin Of Late Wc Stars At High Metallicity?mentioning

confidence: 99%

A spectroscopic search for the non-nuclear Wolf-Rayet population of the metal-rich spiral galaxy M 83

Hadfield

Crowther

Schild

et al. 2005

A&A

View full text Add to dashboard Cite

Abstract. We present a catalogue of non-nuclear regions containing Wolf-Rayet stars in the metal-rich spiral galaxy M 83 (NGC 5236). From a total of 283 candidate regions identified using He  λ4686 imaging with VLT-FORS2, Multi Object Spectroscopy of 198 regions was carried out, confirming 132 WR sources. From this sub-sample, an exceptional content of ∼1035 ± 300 WR stars is inferred, with N(WC)/N(WN) ∼ 1.2, continuing the trend to larger values at higher metallicity amongst Local Group galaxies, and greatly exceeding current evolutionary predictions at high metallicity. Late-type stars dominate the WC population of M 83, with N(WC8-9)/N(WC4-7) = 9 and WO subtypes absent, consistent with metallicity dependent WC winds. Equal numbers of late to early WN stars are observed, again in contrast to current evolutionary predictions. Several sources contain large numbers of WR stars. In particular, #74 (alias region 35 from de Vaucouleurs et al.) contains ∼230 WR stars, and is identified as a Super Star Cluster from inspection of archival HST/ACS images. Omitting this starburst cluster would result in revised statistics of N(WC)/N(WN) ∼ 1 and N(WC8-9)/N(WC4-7) ∼ 6 for the "quiescent" disk population. Including recent results for the nucleus and accounting for incompleteness in our spectroscopic sample, we suspect the total WR population of M 83 may exceed 3000 stars.

show abstract

The fourth catalogue of Population I Wolf-Rayet stars in the Large Magellanic Cloud

Cited by 153 publications

References 72 publications

Evidence of quasi-chemically homogeneous evolution of massive stars up to solar metallicity

Evidence of quasi-chemically homogeneous evolution of massive stars up to solar metallicity

Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies

A spectroscopic search for the non-nuclear Wolf-Rayet population of the metal-rich spiral galaxy M 83

Contact Info

Product

Resources

About