Rotational properties of the O-type star population in the Tarantula region

O.H. Ram'irez-Agudelo$^1$, S. Sim'on-D'{i}az $^{2,3}$, H. Sana$^{1,4}$, A. de Koter$^{1,5}$, C. Sab'{i}n-Sanjul'{i}an$^{2,3}$, S.E. de Mink$^{6,7}$, P. L. Dufton$^{8}$, G. Gr"afener$^{9}$, C.J. Evans$^{10}$, A. Herrero$^{2,3}$, N. Langer$^{11}$, D.J. Lennon$^{12}$, J. Ma'{i}z Apell'aniz$^{13}$, N. Markova$^{14}$, F. Najarro$^{15}$, J. Puls$^{16}$, W.D. Taylor$^{10}$, and
J.S. Vink$^{9}$

$^{1}$ Astronomical Institute Anton Pannekoek, University of Amsterdam, The Netherlands
$^{2}$ Instituto de Astrof'{i}sica de Canarias, C/ V'{i}a L'{a}ctea s/n, E-38200 La Laguna, Tenerife, Spain
$^{3}$ Departamento de Astrof'{i}sica, Universidad de La Laguna, Avda. Astrof'{i}sico Francisco S'{a}nchez s/n, E-38071 La Laguna, Tenerife, Spain
$^{4}$ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
$^{5}$ Instituut voor Sterrenkunde, Universiteit Leuven, Celestijnenlaan 200 D, 3001, Leuven, Belgium
$^{6}$ Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101, USA
$^{7}$ Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA
$^{8}$ Astrophysics Research Centre, School of Mathematics and Physics, Queen's University of Belfast, Belfast BT7 1NN, UK
$^{9}$ Armagh Observatory, College Hill, Armagh, BT61 9DG, Northern Ireland, UK
$^{10}$ UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ, UK
$^{11}$ Argelander-Institut f"ur Astronomie, Universit"at Bonn, Auf dem H"ugel 71, 53121 Bonn, Germany
$^{12}$ European Space Astronomy Centre (ESAC), Camino bajo del Castillo, s/n Urbanizacion Villafranca del Castillo, Villanueva de la Ca~nada, E-28692 Madrid, Spain
$^{13}$ Instituto de Astrof'{i}sica de Andaluc'{i}a-CSIC, Glorieta de la Astronom'ia s/n E-18008 Granada, Spain
$^{14}$ Institute of Astronomy with NAO, Bulgarian Academy of Science, PO Box 136, 4700 Smoljan, Bulgaria
$^{15}$ Centro de Astrobiolog'{i}a (CSIC-INTA), Ctra. de Torrej'on a Ajalvir km-4, E-28850 Torrej'on de Ardoz, Madrid, Spain
$^{16}$ Universit"atssternwarte Scheinerstrasse 1, 81679 M"unchen, Germany

The 30 Doradus (30,Dor) region in the Large Magellanic Cloud (also known as the Tarantula Nebula) is the nearest massive starburst region, containing the richest sample of
massive stars in the Local Group. It is the best possible laboratory to investigate aspects of the formation and evolution of massive stars. Here, we focus on rotation which is a key parameter in the evolution of these objects. We establish the projected rotational velocity, $v_{e}sin i$, distribution of an unprecedented sample of 216 radial
velocity constant ($rm{Delta RV, leq, 20 ,km s^{-1}}$) O-type stars in 30,Dor observed in the framework of the VLT-FLAMES Tarantula Survey (VFTS). The distribution of $v_{e}sin i$ shows a two-component structure: a peak around 80 $rm{km s^{-1}}$ and a high-velocity tail extending up to $sim$600 $rm{km s^{-1}}$. Around 75% of the sample has 0 $leq, v_{e}sin i leq$ 200 $rm{km s^{-1}}$ with the other 25% distributed in the high-velocity tail.
The presence of the low-velocity peak is consistent with that found in other studies of late-O and early-B stars.
The high-velocity tail is compatible with expectations from binary interaction synthesis models and may be predominantly populated by post-binary interaction, spun-up, objects and mergers. This may have important implications for the nature of progenitors of long-duration gamma ray bursts.

Reference: Conference proceedings article: Massive stars: from alpha to Omega, 10-14 June 2013, Rhodes, Greece
Status: Conference proceedings