OH30.1 18cm OH Masers MERLIN
A set of 16 images for the OH 1612 MHz maser emission from the OH/IR
star OH 30.1-0.7. Each image shows the distribution of the maser
emission at a given velocity and corresponds to a cut through the
circumstellar envelope. The colours represent the intensity of the
maser emission. The strongest emission occurs from unresolved cap-like
regions at the front and back of the envelope (first and last
images). At intermediate velocities, weaker emission is detected from
rings which are centred on the stellar position. The radii of the
rings increases towards the central velocity in just the way expected
for a spherical shell of constant radius. However at some velocities
the well resolved images show the masers to be located within several
arc-like filamentary structures. These define knotty regions of
enhanced gas density where the maser emission is strongest.
Chapman(AAO/ATNF), Killeen(ATNF) and van Langevelde(JIVE)