The VLT-FLAMES Tarantula Survey XVIII. Classifications and radial velocities of the B-type stars

Evans, C. J.; Kennedy, M. B.; Dufton, P. L.; Howarth, I. D.; Walborn, N. R.; Markova, N.; Clark, J. S.; de Mink, S. E.; de Koter, A.; Dunstall, P. R.; Hénault-Brunet, V.; Maíz Apellániz, J.; McEvoy, C. M.; Sana, H.; Simón-Díaz, S.; Taylor, W. D. and Vink, J. S. (2015). The VLT-FLAMES Tarantula Survey XVIII. Classifications and radial velocities of the B-type stars. Astronomy & Astrophysics, 574, article no. A13.

DOI: https://doi.org/10.1051/0004-6361/201424414

Abstract

We present spectral classifications for 438 B-type stars observed as part of the VLT-FLAMES Tarantula Survey (VFTS) in the 30 Doradus region of the Large Magellanic Cloud. Radial velocities are provided for 307 apparently single stars, and for 99 targets with radial-velocity variations which are consistent with them being spectroscopic binaries. We investigate the spatial distribution of the radial velocities across the 30 Dor region, and use the results to identify candidate runaway stars. Excluding potential runaways and members of two older clusters in the survey region (SL 639 and Hodge 301), we determine a systemic velocity for 30 Dor of 271.6 ± 12.2 kms^-1 from 273 presumed single stars. Employing a 3σ criterion we identify nine candidate runaway stars (2.9% of the single stars with radial-velocity estimates). The projected rotational velocities of the candidate runaways appear to be significantly different to those of the full B-type sample, with a strong preference for either large (≥345 kms^-1) or small (≤65 kms^-1) rotational velocities. Of the candidate runaways, VFTS 358 (classified B0.5: V) has the largest differential radial velocity (−106.9 ± 16.2 kms^-1), and a preliminary atmospheric analysis finds a significantly enriched nitrogen abundance of 12 + log (N/H) ≳ 8.5. Combined with a large rotational velocity (v_e sin i = 345 ± 22 kms^-1), this is suggestive of past binary interaction for this star.

Viewing alternatives

Metrics

Item Actions

Export

You can export this page using these formats Digital Object Identifier - DOI

About

• Item ORO ID
• 53981
• Item Type
• Journal Item
• ISSN
• 1432-0746
• Keywords
• stars: fundamental parameters; stars: early-type; open clusters and associations: individual: NGC 2060; open clusters and associations: individual: NGC 2070; open clusters and associations: individual: Hodge 301; open clusters and associations: individual: SL 639
• Academic Unit or School
• Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
  Faculty of Science, Technology, Engineering and Mathematics (STEM)
• Research Group
• Astronomy
• Copyright Holders
• © 2015 ESO
• Related URLs
• • http://oro.open.ac.uk/31849/(ORO Item)
  • http://oro.open.ac.uk/35958/(ORO Item)
  • http://oro.open.ac.uk/35961/(ORO Item)
  • http://oro.open.ac.uk/53986/(ORO Item)
  • http://oro.open.ac.uk/53979/(ORO Item)
  • http://oro.open.ac.uk/53983/(ORO Item)
• Depositing User
• J. Simon Clark