CaltechAUTHORS
  A Caltech Library Service

The VLT-FLAMES Tarantula Survey. XII. Rotational velocities of the single O-type stars

Ramírez-Agudelo, O. H. and Simón-Díaz, S. and Sana, H. and de Koter, A. and Sabín-Sanjulían, C. and de Mink, S. E. and Dufton, P. L. and Gräfener, G. and Evans, C. J. and Herrero, A. and Langer, N. and Lennon, D. J. and Maíz Apellániz, J. and Markova, N. and Najarro, F. and Puls, J. and Taylor, W. D. and Vink, J. S. (2013) The VLT-FLAMES Tarantula Survey. XII. Rotational velocities of the single O-type stars. Astronomy and Astrophysics, 560 . Art. No. A29. ISSN 0004-6361. http://resolver.caltech.edu/CaltechAUTHORS:20140129-134710507

[img]
Preview
PDF - Published Version
See Usage Policy.

2376Kb
[img]
Preview
PDF - Submitted Version
See Usage Policy.

2336Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20140129-134710507

Abstract

Context. The 30 Doradus (30 Dor) region of the Large Magellanic Cloud, also known as the Tarantula nebula, is the nearest starburst region. It contains the richest population of massive stars in the Local Group, and it is thus the best possible laboratory to investigate open questions on the formation and evolution of massive stars. Aims. Using ground-based multi-object optical spectroscopy obtained in the framework of the VLT-FLAMES Tarantula Survey (VFTS), we aim to establish the (projected) rotational velocity distribution for a sample of 216 presumably single O-type stars in 30 Dor. The sample is large enough to obtain statistically significant information and to search for variations among subpopulations – in terms of spectral type, luminosity class, and spatial location – in the field of view. Methods. We measured projected rotational velocities, ν_esini, by means of a Fourier transform method and a profile fitting method applied to a set of isolated spectral lines. We also used an iterative deconvolution procedure to infer the probability density, P(ν_e), of the equatorial rotational velocity, ν_e. Results. The distribution of νesini shows a two-component structure: a peak around 80 kms^(-1) and a high-velocity tail extending up to ~600 kms^(-1). This structure is also present in the inferred distribution P(ν_e) with around 80% of the sample having 0 < ν_e ≤ 300 kms^(-1) and the other 20% distributed in the high-velocity region. The presence of the low-velocity peak is consistent with what has been found in other studies for late O- and early B-type stars. Conclusions. Most of the stars in our sample rotate with a rate less than 20% of their break-up velocity. For the bulk of the sample, mass loss in a stellar wind and/or envelope expansion is not efficient enough to significantly spin down these stars within the first few Myr of evolution. If massive-star formation results in stars rotating at birth with a large portion of their break-up velocities, an alternative braking mechanism, possibly magnetic fields, is thus required to explain the present-day rotational properties of the O-type stars in 30 Dor. The presence of a sizeable population of fast rotators is compatible with recent population synthesis computations that investigate the influence of binary evolution on the rotation rate of massive stars. Even though we have excluded stars that show significant radial velocity variations, our sample may have remained contaminated by post-interaction binary products. That the high-velocity tail may be populated primarily (and perhaps exclusively) by post-binary interaction products has important implications for the evolutionary origin of systems that produce gamma-ray bursts.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://arxiv.org/abs/1309.2929arXivDiscussion Paper
http://www.aanda.org/articles/aa/abs/2013/12/aa21986-13/aa21986-13.htmlPublisherArticle
http://dx.doi.org/10.1051/0004-6361/201321986DOIArticle
Additional Information:© 2013 ESO. Article published by EDP Sciences. Received: 29 May 2013. Accepted: 10 September 2013. Published online 03 December 2013. Based on observations collected at the European Southern Observatory under program ID 182.D-0222. S.d.M. acknowledges support by NASA through an Einstein Fellowship grant, PF3-140105, and a Hubble Fellowship grant, HST-HF-51270.01-A, awarded by the STScI operated by AURA under contract NAS5-26555. JMA acknowledges support from the Spanish Government Ministerio de Educación y Ciencia through grants AYA2010-15081 and AYA2010-17631 and the Consejería de Educación of the Junta de Andalucía through grant P08- TIC-4075. SS-D and AH acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2010-21697-C05-04, Consolider-Ingenio 2010 CSD2006-00070, and Severo Ochoa SEV-2011-0187, and by the Canary Islands Government under grant PID2010119. FN ackowledges support by the Spanish MINECO under grants AYA2010-21697-C05-01 and FIS2012-39162-C06-01.
Funders:
Funding AgencyGrant Number
NASA Einstein FellowshipPF3-140105
NASA Hubble FellowshipHST-HF-51270.01-A
NASANAS5-26555
Ministerio de Educación y Ciencia (MEC)AYA2010-15081
Ministerio de Educación y Ciencia (MEC)AYA2010-17631
Consejería de Educación of the Junta de AndalucíaP08- TIC-4075
Ministerio de Economía y Competitividad (MINECO)AYA2010-21697-C05-04
Consolider-Ingenio 2010CSD2006-00070
Severo OchoaSEV-2011-0187
Canary Islands GovernmentPID2010119
Ministerio de Economía y Competitividad (MINECO)AYA2010-21697-C05-01
Ministerio de Economía y Competitividad (MINECO)FIS2012-39162-C06-01
Subject Keywords:stars: early-type, stars: rotation, line: profiles, Magellanic Clouds, galaxies: star clusters: individual: 30 Doradus
Record Number:CaltechAUTHORS:20140129-134710507
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20140129-134710507
Official Citation:The VLT-FLAMES Tarantula Survey - XII. Rotational velocities of the single O-type stars O. H. Ramírez-Agudelo, S. Simón-Díaz, H. Sana, A. de Koter, C. Sabín-Sanjulían, S. E. de Mink, P. L. Dufton, G. Gräfener, C. J. Evans, A. Herrero, N. Langer, D. J. Lennon, J. Maíz Apellániz, N. Markova, F. Najarro, J. Puls, W. D. Taylor and J. S. Vink A&A 560 A29 (2013) DOI: http://dx.doi.org/10.1051/0004-6361/201321986
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:43556
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:29 Jan 2014 22:48
Last Modified:27 Jan 2016 18:51

Repository Staff Only: item control page