1995A&A...293..532M

Further longslit observations of Hα emission line profiles have been obtained over the Honeycomb nebula with the EMMI spectrometer combined with the New Technology Telescope to supplement previous ones obtained with the Manchester Echelle spectrometer on the Anglo-Australian telescope. Spikes extending to -200km/s with respect to the systemic radial velocity are found in the position-velocity arrays over adjacent filamentary edges of the most prominent shell in the Honeycomb complex. Flows are found to predominantly approaching radial velocities over the rest of the shells though a similar spike extends continuously from approaching to receding radial velocities over the perimeter of one particular shell. The origin of these motions in collimated flows of gas whose velocity vectors are nearly along the sight-line is suggested. In fact the Honeycomb nebula may only be unique because of this special orientation of the flows. Various dynamical mechanisms are considered for the formation of the Honeycomb nebula with the collision of a supernova blast wave with the wall of a giant shell as the favoured explanation. An explanation is also sought for the extensive, faint, receding, velocity component to the Hα profiles that is found over the general vicinity of the Honeycomb nebula.