Bibcode
Simon-Diaz, S.; Castro, N.; Herrero, A.; Aerts, C.; Puls, J.; Markova, N.
Referencia bibliográfica
Massive Stars: From α to Ω, held 10-14 June 2013 in Rhodes, Greece; Online at http://a2omega-conference.net, id.28
Advertised on:
6
2013
Número de citas
0
Número de citas referidas
0
Descripción
The analysis of high-resolution spectra of blue massive stars has
allowed us to firmly ascertain the presence of an important
non-rotational broadening in O and B-type stars of all luminosity
classes (see e.g. Simon-Diaz et al. 2011, BSRSL, 80, 514). Despite it
has been commonly referred to as "macroturbulent broadening", results
from the analyses make its interpretation as the effect of turbulent
motions quite improbable. An alternative physical mechanism suggested as
the origin of this extra broadening relates to oscillations. As
indicated by recent simulations by Aerts et al. (2009, A&A, 508,
409) this scenario offers a plausible explanation that is now being
tested observationally (e.g. Simon-Diaz et al. 2010, ApJL, 720, 174).
In this contribution, I will provide an overview of our present
knowledge about this intriguing line-broadening, also summarizing the
main results obtained to date in our project aimed at investigating the
"macroturbulent" broadening in O and B stars and its possible connection
to spectroscopic variability phenomena and stellar oscillations. The
following questions will be treated in this contribution: 1) How v*sin i
measurements in massive stars are affected when "macroturbulent"
broadening is taken into account? 2) Where in the OB star domain is this
extra-broadening present? 3) Is there any dependence of the
characteristics of the "macroturbulent" broadening with metallicity? 4)
Should "macroturbulent" broadening actually be called "pulsational"
broadening? 5) Is this spectroscopic feature a single-snapshot
alternative to detect and investigate stellar pulsations in the realm of
massive stars?