X-Shooting ULLYSES: Massive stars at low metallicity III. Terminal wind speeds of ULLYSES massive stars

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00598282" target="_blank" >RIV/67985815:_____/24:00598282 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0356013" target="_blank" >https://hdl.handle.net/11104/0356013</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202245588" target="_blank" >10.1051/0004-6361/202245588</a>

Result language

angličtina

Original language name

X-Shooting ULLYSES: Massive stars at low metallicity III. Terminal wind speeds of ULLYSES massive stars

Original language description

Context. The winds of massive stars have a significant impact on stellar evolution and on the surrounding medium. The maximum speed reached by these outflows, the terminal wind speed v(infinity), is a global wind parameter and an essential input for models of stellar atmospheres and feedback. With the arrival of the ULLYSES programme, a legacy UV spectroscopic survey with the Hubble Space Telescope, we have the opportunity to quantify the wind speeds of massive stars at sub-solar metallicity (in the Large and Small Magellanic Clouds, 0.5 Z(circle dot) and 0.2 Z(circle dot), respectively) at an unprecedented scale. Aims. We empirically quantify the wind speeds of a large sample of OB stars, including supergiants, giants, and dwarfs at sub-solar metallicity. Using these measurements, we investigate trends of v(infinity) with a number of fundamental stellar parameters, namely effective temperature (T-eff), metallicity (Z), and surface escape velocity v(esc). Methods. We empirically determined v(infinity) for a sample of 149 OB stars in the Magellanic Clouds either by directly measuring the maximum velocity shift of the absorption component of the C IV lambda lambda 1548-1550 line profile, or by fitting synthetic spectra produced using the Sobolev with exact integration method. Stellar parameters were either collected from the literature, obtained using spectral-type calibrations, or predicted from evolutionary models. Results. We find strong trends of v(infinity) with T-eff and v(esc) when the wind is strong enough to cause a saturated P Cygni profile in C IV lambda lambda 1548-1550. We find evidence for a metallicity dependence on the terminal wind speed v(infinity) proportional to Z(0.22 +/- 0.03) when we compared our results to previous Galactic studies. Conclusions. Our results suggest that T-eff rather than v(esc) should be used as a straightforward empirical prediction of v(infinity) and that the observed Z dependence is steeper than suggested by earlier works.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA22-34467S" target="_blank" >GA22-34467S: Binary interaction on the red giant branch: Hot subdwarfs as a test case.</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

688

Issue of the periodical within the volume

Aug.

Country of publishing house

FR - FRANCE

Number of pages

19

Pages from-to

A105

UT code for WoS article

001289291100011

EID of the result in the Scopus database

2-s2.0-85201240773