Parsons, TN;
Prinja, RK;
Bernini-Peron, M;
Fullerton, AW;
Massa, DL;
Oskinova, LM;
Pauli, D;
... Sander, AAC; + view all
(2024)
Optically thick structure in early B-type supergiant stellar winds at low metallicities.
Monthly Notices of the Royal Astronomical Society
, 527
(4)
pp. 11422-11457.
10.1093/mnras/stad3966.
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Abstract
Accurate determination of mass-loss rates from massive stars is important to understand stellar and galactic evolution and enrichment of the interstellar medium. Large-scale structure and variability in stellar winds have significant effects on mass-loss rates. Time-series observations provide direct quantification of such variability. Observations of this nature are available for some Galactic early supergiant stars but not yet for stars in lower metallicity environments such as the Magellanic Clouds. We utilize ultraviolet spectra from the Hubble Space Telescope ULLYSES program to demonstrate that the presence of structure in stellar winds of supergiant stars at low metallicities may be discerned from single-epoch spectra. We find evidence that, for given stellar luminosities and mean stellar wind optical depths, structure is more prevalent at higher metallicities. We confirm, at Large Magellanic Cloud (0.5 Z☉), Small Magellanic Cloud (0.2 Z☉), and lower (0.14–0.1 Z☉) metallicities, earlier Galactic results that there does not appear to be correlation between the degree of structure in stellar winds of massive stars and stellar effective temperature. Similar lack of correlation is found with regard to terminal velocity of stellar winds. Additional and revised values for radial velocities of stars and terminal velocities of stellar winds are presented. Direct evidence of temporal variability, on time-scales of several days, in stellar wind at low metallicity is found. We illustrate that narrow absorption components in wind-formed profiles of Galactic OB stellar spectra remain common in early B supergiant spectra at low metallicities, providing means for better constraining hot, massive star mass-loss rates.
| Type: | Article |
|---|---|
| Title: | Optically thick structure in early B-type supergiant stellar winds at low metallicities |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stad3966 |
| Publisher version: | https://doi.org/10.1093/mnras/stad3966 |
| Language: | English |
| Additional information: | © 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | Stars: early-type, stars: mass-loss, stars: winds, outflows, Magellanic Clouds, ultraviolet: stars |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10186349 |
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