Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds
Massive stars (∼8–25 M _⊙ ) 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 f...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ace5a3 |
| _version_ | 1797391462779846656 |
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| author | Y. Götberg M. R. Drout A. P. Ji J. H. Groh B. A. Ludwig P. A. Crowther N. Smith A. de Koter S. E. de Mink |
| author_facet | Y. Götberg M. R. Drout A. P. Ji J. H. Groh B. A. Ludwig P. A. Crowther N. Smith A. de Koter S. E. de Mink |
| author_sort | Y. Götberg |
| collection | DOAJ |
| description | Massive stars (∼8–25 M _⊙ ) 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 ( T _eff ∼ 50–100 kK), high surface gravities ( $\mathrm{log}g\sim $ 5), and hydrogen-poor/helium-rich surfaces ( X _H,surf ∼ 0–0.4) while showing for the first time a range of bolometric luminosities (10 ^3 –10 ^5 L _⊙ ), small radii (∼0.5–1 R _⊙ ), and low Eddington factors (Γ _e ∼ 0.006–0.4). Using these properties, we derive intermediate current masses (∼1–8 M _⊙ ), which suggest that their progenitors were massive stars (∼5–25 M _⊙ ) 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 ( ${\dot{M}}_{\mathrm{wind}}\lesssim {10}^{-9}$ M _⊙ 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. |
| first_indexed | 2024-03-08T23:33:01Z |
| format | Article |
| id | doaj.art-a9625e8ed06e44da88cb99db67b71850 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T23:33:01Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-a9625e8ed06e44da88cb99db67b718502023-12-14T10:51:16ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01959212510.3847/1538-4357/ace5a3Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic CloudsY. Götberg0https://orcid.org/0000-0002-6960-6911M. R. Drout1https://orcid.org/0000-0001-7081-0082A. P. Ji2https://orcid.org/0000-0002-4863-8842J. H. Groh3B. A. Ludwig4P. A. Crowther5https://orcid.org/0000-0001-6000-6920N. Smith6https://orcid.org/0000-0001-5510-2424A. de Koter7S. E. de Mink8https://orcid.org/0000-0001-9336-2825The Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA ; ygoetberg@carnegiescience.eduDavid A. Dunlap Department of Astronomy and Astrophysics, University of Toronto , 50 St. George Street, Toronto, Ontario, M5S 3H4 Canada ; maria.drout@utoronto.caDepartment of Astronomy & Astrophysics, University of Chicago , 5640 S Ellis Avenue, Chicago, IL 60637, USAIndependent ResearcherDavid A. Dunlap Department of Astronomy and Astrophysics, University of Toronto , 50 St. George Street, Toronto, Ontario, M5S 3H4 Canada ; maria.drout@utoronto.caDepartment of Physics and Astronomy, University of Sheffield , Hicks Building, Hounsfield Road, Sheffield S3 7RH, UKSteward Observatory, University of Arizona 933 N. Cherry Avenue, Tucson, AZ 85721, USAAnton Pannekoek Institute for Astronomy, University of Amsterdam , Science Park 904, NL-1098 XH Amsterdam, The Netherlands; Institute of Astronomy , KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, BelgiumAnton Pannekoek Institute for Astronomy, University of Amsterdam , Science Park 904, NL-1098 XH Amsterdam, The Netherlands; Max-Planck-Institut für Astrophysik , Karl-Schwarzschild-Straße 1, D-85741 Garching, GermanyMassive stars (∼8–25 M _⊙ ) 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 ( T _eff ∼ 50–100 kK), high surface gravities ( $\mathrm{log}g\sim $ 5), and hydrogen-poor/helium-rich surfaces ( X _H,surf ∼ 0–0.4) while showing for the first time a range of bolometric luminosities (10 ^3 –10 ^5 L _⊙ ), small radii (∼0.5–1 R _⊙ ), and low Eddington factors (Γ _e ∼ 0.006–0.4). Using these properties, we derive intermediate current masses (∼1–8 M _⊙ ), which suggest that their progenitors were massive stars (∼5–25 M _⊙ ) 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 ( ${\dot{M}}_{\mathrm{wind}}\lesssim {10}^{-9}$ M _⊙ 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.https://doi.org/10.3847/1538-4357/ace5a3Binary starsClose binary starsInteracting binary starsEarly-type starsHelium-rich starsHelium burning |
| spellingShingle | Y. Götberg M. R. Drout A. P. Ji J. H. Groh B. A. Ludwig P. A. Crowther N. Smith A. de Koter S. E. de Mink Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds The Astrophysical Journal Binary stars Close binary stars Interacting binary stars Early-type stars Helium-rich stars Helium burning |
| title | Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds |
| title_full | Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds |
| title_fullStr | Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds |
| title_full_unstemmed | Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds |
| title_short | Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds |
| title_sort | stellar properties of observed stars stripped in binaries in the magellanic clouds |
| topic | Binary stars Close binary stars Interacting binary stars Early-type stars Helium-rich stars Helium burning |
| url | https://doi.org/10.3847/1538-4357/ace5a3 |
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