Spiral Waves in an Accretion Disc (I)
Two Doppler tomograms constructed from the emission line observations of IP
Peg on the rise to an outburst
(bottom panels). Left shows an image constructed
from the Hydrogen emission, the image on the right from the Helium emission.
The top panels show the observed emission line
profiles from which the bottom maps are constructed. The bright spot near the
center is emission from the mass donating companion
star. The expected ballistic trajectory from material leaving this star is
plotted
to the left of it. Upper cross is the common center
of mass of the binary, while the lower cross denotes the position of the white
dwarf, not visible in the optical line emission.
Most of its energy is radiated in the UV/X-ray regime. The emission of the
accretion
disc forms a two armed trailing spiral around the
white dwarf, closely resembling predicted models based on theoretical work on
this tidal interaction. D. Steeghs, E. Harlaftis,
K. Horne (Astronomy Group, Univ. St.Andrews).
Javier Méndez
jma@ing.iac.es