A fast spinning magnetic white dwarf in the double degenerate, super-Chandrasekhar system NLTT 12758

0479176 - ASÚ 2018 RIV GB eng J - Článek v odborném periodiku
Kawka, Adela - Briggs, G. - Vennes, Stephane - Ferrario, L. - Paunzen, E. - Wickramasinghe, D.T.
A fast spinning magnetic white dwarf in the double degenerate, super-Chandrasekhar system NLTT 12758.
Monthly Notices of the Royal Astronomical Society. Roč. 466, č. 1 (2017), s. 1127-1139. ISSN 0035-8711. E-ISSN 1365-2966
Grant CEP: GA ČR GAP209/12/0217; GA ČR GA15-15943S; GA MŠMT LG14013; GA MŠMT(CZ) LG15010
Institucionální podpora: RVO:67985815
Klíčová slova: close binaries * NLTT 12758 * magnetic field
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.194, rok: 2017

We present an analysis of the close double degenerate NLTT 12758, which is comprised of a magnetic white dwarf with a field of about 3.1 MG and an apparently non-magnetic white dwarf. We measured an orbital period of 1.154 d and found that the magnetic white dwarf is spinning around its axis with a period of 23 min. An analysis of the atmospheric parameters has revealed that the cooling ages of the two white dwarfs are comparable, suggesting that they formed within a short period of time from each other. Our modelling indicates that the non-magnetic white dwarf is more massive (M = 0.83M(circle dot)) than its magnetic companion (M = 0.69M(circle dot)) and that the total mass of the system is higher than the Chandrasekhar mass. Although the stars will not come into contact over a Hubble time, when they do come into contact, dynamically unstable mass transfer will take place leading to either an accretion induced collapse into a rapidly spinning neutron star or a Type Ia supernova.
Trvalý link: http://hdl.handle.net/11104/0275176