AffiliationUniv Arizona, Steward Observ
stars: kinematics and dynamics
open clusters and associations: individual: Carina Nebula
MetadataShow full item record
PublisherOXFORD UNIV PRESS
CitationMegan M Kiminki, Nathan Smith; A radial velocity survey of the Carina Nebula's O-type stars, Monthly Notices of the Royal Astronomical Society, Volume 477, Issue 2, 21 June 2018, Pages 2068–2086, https://doi.org/10.1093/mnras/sty748
Rights© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
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AbstractWe have obtained multi-epoch observations of 31 O-type stars in the Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m telescope. We measure their radial velocities to 1-2 km s(-1) precision and present new or updated orbital solutions for the binary systems HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial velocities from the literature for 32 additional O-type and evolved massive stars in the region. The combined data set shows a mean heliocentric radial velocity of 0.6 km s(-1). We calculate a velocity dispersion of <= 9.1 km s(-1), consistent with an unbound, substructured OB association. The Tr 14 cluster shows a marginally significant 5 km s(-1) radial velocity offset from its neighbour Tr 16, but there are otherwise no correlations between stellar position and velocity. The O-type stars in Cr 228 and the South Pillars region have a lower velocity dispersion than the region as a whole, supporting a model of distributed massive star formation rather than migration from the central clusters. We compare our stellar velocities to the Carina Nebula's molecular gas and find that Tr 14 shows a close kinematic association with the Northern Cloud. In contrast, Tr 16 has accelerated the Southern Cloud by 10-15 km s(-1), possibly triggering further massive star formation. The expansion of the surrounding HII region is not symmetric about the O-type stars in radial velocity space, indicating that the ionized gas is constrained by denser material on the far side.
VersionFinal published version
SponsorsCommonwealth of Australia