Bibcode
Ramírez-Agudelo, O. H.; Sana, H.; de Koter, A.; Simón-Díaz, S.; de Mink, S. E.; Tramper, F.; Dufton, P. L.; Evans, C. J.; Gräfener, G.; Herrero, A.; Langer, N.; Lennon, D. J.; Maíz Apellániz, J.; Markova, N.; Najarro, F.; Puls, J.; Taylor, W. D.; Vink, J. S.
Referencia bibliográfica
New windows on massive stars: asteroseismology, interferometry, and spectropolarimetry, Proceedings of the International Astronomical Union, IAU Symposium, Volume 307, pp. 76-81
Fecha de publicación:
1
2015
Número de citas
2
Número de citas referidas
2
Descripción
Rotation is a key parameter in the evolution of massive stars, affecting
their evolution, chemical yields, ionizing photon budget, and final
fate. We determined the projected rotational velocity, υ
e sin i, of ~330 O-type objects, i.e. ~210 spectroscopic
single stars and ~110 primaries in binary systems, in the Tarantula
nebula or 30 Doradus (30 Dor) region. The observations were taken using
VLT/FLAMES and constitute the largest homogeneous dataset of multi-epoch
spectroscopy of O-type stars currently available. The most distinctive
feature of the υ e sin i distributions of the
presumed-single stars and primaries in 30 Dor is a low-velocity peak at
around 100 km s-1. Stellar winds are not expected to have
spun-down the bulk of the stars significantly since their arrival on the
main sequence and therefore the peak in the single star sample is likely
to represent the outcome of the formation process. Whereas the spin
distribution of presumed-single stars shows a well developed tail of
stars rotating more rapidly than 300 km s-1, the sample of
primaries does not feature such a high-velocity tail. The tail of the
presumed-single star distribution is attributed for the most part - and
could potentially be completely due - to spun-up binary products that
appear as single stars or that have merged. This would be consistent
with the lack of such post-interaction products in the binary sample,
that is expected to be dominated by pre-interaction systems. The peak in
this distribution is broader and is shifted toward somewhat higher spin
rates compared to the distribution of presumed-single stars. Systems
displaying large radial velocity variations, typical for short period
systems, appear mostly responsible for these differences.