X-Ray Bursters
In an X-ray burster
the mechanism is thought to be similar to a nova, except that
the star onto which the matter accretes is a neutron star rather than a white dwarf.
The diagram adjacent right illustrates.
Thermonuclear Runaway
The X-ray burst is triggered by a thermonuclear runaway under degenerate conditions, as for a
nova.
However, the
gravitational field of a neutron star is much stronger than that of a white dwarf. Thus,
matter falling to the surface of the neutron star is accelerated to high velocities
and the thermonuclear runaway triggered by the accretion
occurs at much higher temperatures and densities than in the nova outburst.
This in turn
tends to produce X-rays rather than visible light in the thermonuclear runaway. The following
diagram illustrates schematically the likely burster mechanism.
