Götberg, Y. orcid.org/0000-0002-6960-6911, Drout, M.R. orcid.org/0000-0001-7081-0082, Ji, A.P. orcid.org/0000-0002-4863-8842 et al. (6 more authors) (2023) Stellar properties of observed stars stripped in binaries in the magellanic clouds. The Astrophysical Journal, 959 (2). 125. ISSN 0004-637X
Abstract
Massive stars (∼8–25 Me) stripped of their hydrogen-rich envelopes via binary interaction are thought to be the main progenitors for merging neutron stars and stripped-envelope supernovae. We recently presented the discovery of the first set of such stripped stars in a companion paper. Here, we fit the spectra of 10 stars with new atmosphere models in order to constrain their stellar properties precisely. We find that the stellar properties align well with the theoretical expectations from binary evolution models for helium-core burning envelope-stripped stars. The fits confirm that the stars have high effective temperatures (Teff ∼ 50–100 kK), high surface gravities (log g~ 5), and hydrogen-poor/helium-rich surfaces (XH,surf ∼ 0–0.4) while showing for the first time a range of bolometric luminosities (103 –105 Le), small radii (∼0.5–1 Re), and low Eddington factors (Γe ∼ 0.006–0.4). Using these properties, we derive intermediate current masses (∼1–8 Me), which suggest that their progenitors were massive stars (∼5–25 Me) and that a subset will reach core-collapse, leaving behind neutron stars or black holes. Using the model fits, we also estimate the emission rates of ionizing photons for these stars, which agree well with previous model expectations. Further, by computing models for a range of mass-loss rates, we find that the stellar winds are weaker than predicted by any existing scheme (Mwind 10 -9 Me yr−1). The properties of this first sample of intermediate-mass helium stars suggest they both contain progenitors of type Ib and IIb supernovae, and provide important benchmarks for binary evolution and population synthesis models.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence (http://creativecommons.org/licenses/by/4.0/). Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 19 Dec 2023 11:49 |
Last Modified: | 19 Dec 2023 11:49 |
Status: | Published |
Publisher: | American Astronomical Society |
Refereed: | Yes |
Identification Number: | 10.3847/1538-4357/ace5a3 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:206734 |