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

C. J. Evans, M. B. Kennedy, P. L. Dufton, I. D. Howarth, N. R. Walborn, N. Markova, J. S. Clark, S. E. De Mink, A. De Koter, P. R. Dunstall, V. Hénault-Brunet, J. Maíz Apellániz, Catherine McEvoy, H. Sana, S. Simón-Díaz, W. D. Taylor, J. S. Vink

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

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 km s-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 km s-1) or small (≤65 km s-1) rotational velocities. Of the candidate runaways, VFTS 358 (classified B0.5: V) has the largest differential radial velocity (-106.9 ± 16.2 km s-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 (υe sin i = 345 ± 22 km s-1), this is suggestive of past binary interaction for this star.

Original languageEnglish
Article numberA13
Number of pages40
JournalAstronomy and Astrophysics
Volume574
Early online date16 Jan 2015
DOIs
Publication statusPublished - 01 Feb 2015

Keywords

  • Open clusters and associations: individual: Hodge 301
  • Open clusters and associations: individual: NGC 2060
  • Open clusters and associations: individual: NGC 2070
  • Open clusters and associations: individual: SL 639
  • Stars: early-type
  • Stars: fundamental parameters

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint Dive into the research topics of 'The VLT-FLAMES Tarantula Survey: XVIII. Classifications and radial velocities of the B-type stars'. Together they form a unique fingerprint.

Cite this