Ultraviolet spectroscopy of the supernova Ia hypervelocity runaway white dwarf J0927-6335

Abstract

The hot white dwarf (WD) J0927-6335 (Gaia DR3 5250394728194220800, effective temperature T${}_{\mathrm{eff}}$ = 60,000 K, surface gravity log g = 7) was detected as the fastest known Galactic hypervelocity star with a space velocity of $\approx$2800 km s${}^{-1}$ and an atmosphere dominated by carbon and oxygen. It is thought to be the surviving WD donor predicted by the "dynamically driven double-degenerate double-detonation" (D${}^6$) type Ia supernova formation model. We analysed an ultraviolet spectrum of J0927-6335 obtained recently with the Hubble Space Telescope and found very high abundances of iron and nickel. This could originate in the pollution of the remnant by the SN Ia explosion but it is uncertain to what extent atomic diffusion altered the chemical composition of the accreted material.

A&A Letters, accepted

References in corpus (5)

• Updated Gaia-2MASS 3D maps of Galactic interstellar dust
• Type Ia Supernova Explosions in Binary Systems: A Review
• A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from The Enhanced Abundances of Nickel and Manganese
• A transiting brown dwarf in a 2 hour orbit
• Type Ia Supernova Nucleosynthesis: Metallicity-Dependent Yields

Cited by in corpus (1)

• The origin of hypervelocity white dwarfs in the merger-disruption of He-CO white dwarfs