Laboratory analogue of a supersonic accretion column in a binary star system

J. Cross (1) , G. Gregori (1) , J. Foster , P. Graham , J. -M. Bonnet-Bidaud (2) , C. Busschaert (3) , N. Charpentier , C. Danson (4) , H. Doyle (5) , R. Drake , J. Fyrth , E. Gumbrell , M. Koenig (6) , C. Krauland , C. Kuranz , B. Loupias , C. Michaut (7, 3) , M. Mouchet (3) , S. Patankar , J. Skidmore (8) , C. Spindloe (9) , E. Tubman , N. Woolsey (10) , R. Yurchak , E. Falize (11)

1 Department of Physics [Oxford]
2 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
3 LUTH (UMR_8102) - Laboratoire Univers et Théories
4 CLF - Central Laser Facility
5 Tyndall National Institute
6 LULI - Laboratoire pour l'utilisation des lasers intenses
7 IPGP - Institut de Physique du Globe de Paris
8 SRON - SRON Netherlands Institute for Space Research
9 RAL - STFC Rutherford Appleton Laboratory
10 Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
11 DAM/DIF - DAM Île-de-France

Astrophysical flows exhibit rich behaviour resulting from the interplay of different forms of energy-gravitational, thermal, magnetic and radiative. For magnetic cataclysmic variable stars, material from a late, main sequence star is pulled onto a highly magnetized (B410 MG) white dwarf. The magnetic field is sufficiently large to direct the flow as an accretion column onto the poles of the white dwarf, a star subclass known as AM Herculis. A stationary radiative shock is expected to form 100-1,000 km above the surface of the white dwarf, far too small to be resolved with current telescopes. Here we report the results of a laboratory experiment showing the evolution of a reverse shock when both ionization and radiative losses are important. We find that the stand-off position of the shock agrees with radiation hydrodynamic simulations and is consistent, when scaled to AM Herculis star systems, with theoretical predictions.

Domaines: Physique [physics]; Astrophysique [astro-ph]

J. Cross, G. Gregori, J. Foster, P. Graham, J. -M. Bonnet-Bidaud, et al.. Laboratory analogue of a supersonic accretion column in a binary star system. Nature Communications, 2016, 7 (1), ⟨10.1038/ncomms11899⟩. ⟨hal-02338839⟩