The Optically Thick Rotating Magnetic Wind from a Massive White Dwarf Merger Product
Abstract
WD J005311 is a newly identified white dwarf (WD) in a mid-infrared nebula. The spectroscopic observation indicates the existence of a neon-enriched carbon/oxygen wind with a terminal velocity of {v}∞ ,{obs} ∼ 16,000 {km} {{{s}}}-1 and a mass-loss rate of {\dot{M}}obs}∼ 3.5× {10}-6 {M}⊙ {yr}}-1. Here we consistently explain the properties of WD J005311 using a newly constructed wind solution, where the optically thick outflow is launched from the carbon-burning shell on an oxygen-neon core and accelerated by the rotating magnetic field to become supersonic and unbound well below the photosphere. Our model implies that WD J005311 has a mass of M * ∼ 1.1-1.3 M ⊙, a magnetic field of B * ∼ (2-5) × 107 G, and a spin angular frequency of Ω ∼ 0.2-0.5 s-1. The large magnetic field and fast spin support the carbon-oxygen WD merger origin. WD J005311 will neither explode as a type Ia supernova nor collapse into a neutron star. If the wind continues to blow another few kyr, WD J005311 will spin down significantly and join to the known sequence of slowly rotating magnetic WDs. Otherwise it may appear as a fast-spinning magnetic WD and could be a new high-energy source.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2019
- DOI:
- 10.3847/1538-4357/ab4e97
- arXiv:
- arXiv:1907.12317
- Bibcode:
- 2019ApJ...887...39K
- Keywords:
-
- White dwarf stars;
- Stellar winds;
- Stellar rotation;
- 1799;
- 1636;
- 1629;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 11 pages, 5 figures, accepted for publication in ApJ