Observational signatures of the surviving donor star in the double detonation model of Type Ia supernovae

Abstract

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

References in corpus (22)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Double-detonation sub-Chandrasekhar supernovae: can minimum helium shell masses detonate the core?
• Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries
• Double-detonation supernovae of sub-Chandrasekhar mass white dwarfs
• Constraining the Type Ia Supernova Progenitor: The Search for Hydrogen in Nebular Spectra
• Unstable Helium Shell Burning on Accreting White Dwarfs
• The Initiation and Propagation of Helium Detonations in White Dwarf Envelopes
• The fastest unbound star in our Galaxy ejected by a thermonuclear supernova
• The hot subdwarf B + white dwarf binary KPD 1930+2752 - a Supernova Type Ia progenitor candidate
• The impact of type Ia supernovae on main sequence binary companions
• Three-dimensional simulations of the interaction between Type Ia supernova ejecta and their main sequence companions
• Double Detonations with Thin, Modestly Enriched Helium Layers Can Make Normal Type Ia Supernovae
• Maximum speed of hypervelocity stars ejected from binaries
• Double detonations of sub-Chandrasekhar mass CO white dwarfs: Can different core and He shell masses explain variations of Type Ia supernovae?
• SNe Ia from double detonations: Impact of core-shell mixing on the carbon ignition mechanism
• Wait for it: Post-supernova winds driven by delayed radioactive decays
• Proper Motions and Trajectories for 16 Extreme Runaway and Hypervelocity Stars
• Search for surviving companions in type Ia supernova remnants
• Velocity limits in the thermonuclear supernova ejection scenario for hypervelocity stars and the origin of US 708
• The interaction of Type Iax supernova ejecta with a helium companion star
• Long-term evolution of surviving companion stars of Type Iax supernovae
• Predicted spatial and velocity distributions of ejected companion stars of helium accretion-induced thermonuclear supernovae

Cited by in corpus (11)

• Discovery of a double detonation thermonuclear supernova progenitor
• Searching for a Hypervelocity White Dwarf Companion: A Proper Motion Survey of SN 1006
• Common envelope to explosion delay time distribution (CEEDTD) of type Ia supernovae
• Evolution of Main-Sequence-like Surviving Companions in Type Ia Supernova Remnants
• Properties and applications of a predicted population of runaway He-sdO/B stars ejected from single degenerate He-donor SNe
• Type Ia supernova ejecta-donor interaction: explosion model comparison
• White dwarf -- red giant star binaries as Type Ia supernova progenitors: with and without magnetic confinement
• Long-term evolution of post-explosion Helium-star Companions of Type Iax Supernovae
• The core degenerate scenario for the type Ia supernova SN 2020eyj
• On the rotation properties of a post-explosion helium-star companion in Type Iax supernovae
• Pre-explosion helium shell flash in type Ia supernovae