@article{f0050f2fdce9404ba27523ff243f7b8f,
title = "Extreme isolation of WN3/O3 stars and implications for their evolutionary origin as the elusive stripped binaries",
abstract = "Recent surveys of the Magellanic Clouds have revealed a subtype of Wolf-Rayet (WR) star with peculiar properties. WN3/O3 spectra exhibit both WR-like emission and O3 V-like absorption - but at lower luminosity than O3 V or WN stars. We examine the projected spatial distribution of WN3/O3 stars in the Large Magellanic Cloud as compared to O-type stars. Surprisingly, WN3/O3 stars are among the most isolated of all classes of massive stars; they have a distribution similar to red supergiants dominated by initial masses of 10-15M⊙, and are far more dispersed than classical WR stars or luminous blue variables. Their lack of association with clusters of O-type stars suggests strongly that WN3/O3 stars are not the descendants of single massive stars (30M⊙ or above). Instead, they are likely products of interacting binaries at lower initial mass (10-18M⊙). Comparison with binary models suggests a probable origin with primaries in this mass range that were stripped of their H envelopes through non-conservative mass transfer by a low-mass secondary. We show that model spectra and positions on the Hertzsprung-Russell diagram for binary-stripped stars are consistent with WN3/O3 stars. Monitoring radial velocities with high-resolution spectra can test for low-mass companions or runaway velocities.With lower initialmass and environments that avoid very massive stars, theWN3/O3 stars fit expectations for progenitors of Type Ib and possibly Type Ibn supernovae.",
keywords = "Stars: Wolf-Rayet, Stars: evolution, Stars: massive, Stars: winds, outflows",
author = "Nathan Smith and Ylva G{\"o}tberg and {de Mink}, {Selma E.}",
note = "Funding Information: The authors wish to acknowledge Jose Groh, Norbert Langer, Hugues Sana, Manos Zapartas, Mathieu Renzo, Alex de Koter, and Max Moe for numerous stimulating discussions. Support for NS was provided by NSF awards AST-1312221 and AST-1515559, by a Scialog grant from the Research Corporation for Science Advancement, and by the National Aeronautics and Space Administration (NASA) through HST grant AR-14316 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. SdM has received funding from the European Union{\textquoteright}s Horizon 2020 research and innovation programme under grant agreement No. 715063 and under the Marie Sk{\l}odowska-Curie grant agreement No. 661502. The authors further acknowledge hospitality of the Kavli Institute for Theoretical Physics, Santa Barbara, CA. Their stay was supported by the National Science Foundation under Grant No. NSF PHY11-25915. This research has made use of the SIMBAD data base, operated at CDS, Strasbourg, France. Funding Information: The authors wish to acknowledge Jose Groh, Norbert Langer, Hugues Sana, Manos Zapartas, Mathieu Renzo, Alex de Koter, and Max Moe for numerous stimulating discussions. Support for NS was provided by NSF awards AST-1312221 and AST-1515559, by a Scialog grant from the Research Corporation for Science Advancement, and by the National Aeronautics and Space Administration (NASA) through HST grant AR-14316 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555. SdM has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 715063 and under the Marie Sklodowska-Curie grant agreement No. 661502. The authors further acknowledge hospitality of the Kavli Institute for Theoretical Physics, Santa Barbara, CA. Their stay was supported by the National Science Foundation under Grant No. NSF PHY11-25915. This research has made use of the SIMBAD data base, operated at CDS, Strasbourg, France. Publisher Copyright: {\textcopyright} 2017 The Author(s).",
year = "2018",
month = mar,
day = "21",
doi = "10.1093/mnras/stx3181",
language = "English (US)",
volume = "475",
pages = "772--782",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}