Observational signatures of the surviving donor star in the double detonation model of Type Ia supernovae
| Autor: | Alexander Heger, Yaotian Zeng, Zheng-Wei Liu, Friedrich K. Röpke |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Orbital speed
Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010306 general physics Ejecta 010303 astronomy & astrophysics Stellar evolution Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Physics High Energy Astrophysical Phenomena (astro-ph.HE) Astronomy and Astrophysics Observable Galaxy 3. Good health Supernova Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Globular cluster Astrophysics::Earth and Planetary Astrophysics Astrophysics - High Energy Astrophysical Phenomena |
| Popis: | The sub-Chandrasekhar mass double-detonation (DDet) scenario is a contemporary model for SNe Ia. The donor star in the DDet scenario is expected to survive the explosion and to be ejected at the high orbital velocity of a compact binary system. For the first time, we consistently perform 3D hydrodynamical simulations of the interaction of SN ejecta with a helium (He) star companion within the DDet scenario. We map the outcomes of 3D impact simulations into 1D stellar evolution codes and follow the long-term evolution of the surviving He-star companions. Our main goal is to provide the post-impact observable signatures of surviving He-star companions of DDet SNe Ia, which will support the search for such companions in future observations. We find that our surviving He-star companions become significantly overluminous for about 1e6 yr during the thermal re-equilibration phase. After the star re-establishes thermal equilibrium, its observational properties are not sensitive to the details of the ejecta-donor interaction. We apply our results to hypervelocity star US 708, which is the fastest unbound star in our Galaxy, travelling with a velocity of about 1200 km/s, making it natural candidate for an ejected donor remnant of a DDet SN Ia. We find that a He-star donor with an initial mass of >0.5 Msun is needed to explain the observed properties of US 708. Based on our detailed binary evolution calculations, however, the progenitor system with such a massive He-star donor cannot get close enough at the moment of SN explosion to explain the high velocity of US 708. Instead, if US 708 is indeed the surviving He-star donor of a DDet SN~Ia, it would require the entire pre-SN progenitor binary to travel at a velocity of about 400 km/s. It could, for example, have been ejected from a globular cluster in the direction of the current motion of the surviving donor star. 11 pages, 9 figures, 1 table, accepted for publication in A&A |
| Databáze: | OpenAIRE |
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