Rate, G. and Crowther, P.A. (2020) Unlocking Galactic Wolf-Rayet stars with Gaia DR2 I: Distances and absolute magnitudes. Monthly Notices of the Royal Astronomical Society, 493 (1). pp. 1512-1529. ISSN 0035-8711
Abstract
We obtain distances to 383 Galactic Wolf-Rayet (WR) stars from Gaia DR2 parallaxes and Bayesian methods, with a prior based on HII regions and dust extinction. Distances agree with those from Bailer-Jones et al. for stars up to 2 kpc from the Sun, though deviate thereafter due to differing priors, leading to modest reductions in luminosities for recent WR spectroscopic results. We calculate visual and K-band absolute magnitudes, accounting for dust extinction contributions and binarity, and identify 188 stars with reliable absolute magnitudes. For WR and O stars within 2 kpc, we find a WR/O ratio of 0.1. The distances are used to generate absolute magnitude calibrations and obtain the Gaia colour magnitude diagram for WR stars. Average vWR-band absolute magnitudes for WN stars range from –3.6 mag (WN3–4) to –7.0 mag (WN8–9ha), and –3.1 (WO2–4) to –4.6 mag (WC9), with standard deviations of ∼0.6 mag. Using HII region scale heights, we identify 31 WR stars at large (3σ, |z|≥156 pc) distances from the mid-plane as potential runaways accounting for the Galactic warp, of which only 4 involve WN8–9 stars, contrary to previous claims.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This is an author-produced version of a paper subsequently published in Monthly Notices of the Royal Astronomical Society. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | stars: Wolf-Rayet; stars: massive; stars: distances; Galaxy: disc |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 03 Feb 2020 13:21 |
Last Modified: | 07 Dec 2021 16:22 |
Status: | Published |
Publisher: | Oxford University Press (OUP) |
Refereed: | Yes |
Identification Number: | 10.1093/mnras/stz3614 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:156335 |