Journal article
Understanding structure in line-driven stellar winds using ultraviolet spectropolarimetry in the time domain
Astrophysics and space science, Vol.367(12), p.123
12/01/2022
DOI: 10.1007/s10509-022-04142-6
Abstract
The most massive stars are thought to lose a significant fraction of their mass in a steady wind during the main-sequence and blue supergiant phases. This in turn sets the stage for their further evolution and eventual supernova, and preconditions the surrounding medium for all following events, with consequences for ISM energization, chemical enrichment, and dust formation. Understanding these processes requires accurate observational constraints on the mass-loss rates of the most luminous stars, which can also be used to test theories of stellar wind driving. In the past, mass-loss rates have been characterized via collisional emission processes such as optical H alpha and free-free radio emission, but these so-called "density squared" diagnostics require correction in the presence of widespread clumping. Recent observational and theoretical evidence points to the likelihood of a ubiquitously high level of such clumping in hot-star winds, but quantifying its effects requires a deeper understanding of the complex dynamics of radiatively driven winds and their stochastic instabilities. Furthermore, large-scale structures initiating in surface anisotropies and propagating throughout the wind can also affect wind driving and alter mass-loss diagnostics. Time series spectroscopy of high resonance-line opacity in the UV, capable of high resolution and high signal-to-noise, are required to better understand these complex dynamics, and more accurately determine mass-loss rates. The proposed Polstar mission (Scowen et al. 2022, this volume) provides the necessary resolution at the Sobolev (similar to 10 km s(-1)) or sound-speed (similar to 20 km s(-1)) scale, for over three dozen bright galactic massive stars with signal-to noise an order of magnitude above that of the celebrated MEGA campaign (Massa et al. 1995) of the International Ultraviolet Explorer (IUE), via continuous observations that track propagating structures through the winds in real time. Supporting geometric constraints are provided by the polarimetric capabilities present in all the datasets of such a mission.
Details
- Title: Subtitle
- Understanding structure in line-driven stellar winds using ultraviolet spectropolarimetry in the time domain
- Creators
- Kenneth G. Gayley - University of IowaJorick S. Vink - Armagh Observatory & PlanetariumAsif Ud-Doula - University of ScrantonAlexandre David-Uraz - Howard UniversityRichard Ignace - East Tennessee State UniversityRaman Prinja - University College LondonNicole St-Louis - Université de MontréalSylvia Ekstrom - University of GenevaYael Naze - University of LiègeTomer Shenar - University of AmsterdamPaul A. Scowen - NASA/GSFC, Greenbelt, USANatallia Sudnik - Nicolaus Copernicus Astronomical CenterStan P. Owocki - University of DelawareJon O. Sundqvist - Institute of AstronomyFlorian A. Driessen - Institute of AstronomyLevin Hennicker - Institute of Astronomy
- Resource Type
- Journal article
- Publication Details
- Astrophysics and space science, Vol.367(12), p.123
- DOI
- 10.1007/s10509-022-04142-6
- ISSN
- 0004-640X
- eISSN
- 1572-946X
- Publisher
- Springer Nature
- Number of pages
- 17
- Grant note
- Fonds National de la Recherche Scientifique (Belgium); Fonds de la Recherche Scientifique - FNRS NAS8-03060 / NASA through Chandra Award by Chandra X-ray Observatory 27 Center PPN/SZN/2020/1/00016/U/DRAFT/00001/U/00001 / NAWA; Polish National Agency for Academic Exchange (NAWA) 80GSFC21M0002; TM1-22001B / NASA; National Aeronautics & Space Administration (NASA) NASA Goddard Space Flight Center; National Aeronautics & Space Administration (NASA) G0H9218N / Odysseus program of the Belgian Research Foundation Flanders (FWO) Belgian Federal Science Policy Office (BELSPO); Belgian Federal Science Policy Office AST-2009412 / National Science Foundation; National Science Foundation (NSF) European Space Agency (ESA); European Space Agency; European Commission CA 16117 / COST Action ChETEC - COST (European Cooperation in Science and Technology) 833925 / STAREX grant from the ERC Horizon 2020 research and innovation programme; European Research Council (ERC)
- Language
- English
- Date published
- 12/01/2022
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984429015602771
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