D. Jones, D. L. Mitchell, M. Lloyd, D. Pollacco, T. J. O'Brien, J. Meaburn, N. M. H. Vaytet
We present the first detailed spatio-kinematical analysis and modelling of
the planetary nebula Shapley 1 (Sp 1), which is known to contain a close-binary
central star system. Close-binary central stars have been identified as a
likely source of shaping in planetary nebulae, but with little observational
support to date. Deep narrowband imaging in the light of [O III] {\lambda}5007A
suggests the presence of a large bow-shock to the west of the nebula,
indicating that it is undergoing the first stages of an interaction with the
interstellar medium. Further narrowband imaging in the light of H{\alpha}+[NII]
{\lambda}6584A combined with longslit observations of the H{\alpha} emission
have been used to develop a spatio-kinematical model of Sp 1. The model clearly
reveals Sp 1 to be a bipolar, axisymmetric structure viewed almost pole-on. The
symmetry axis of the model nebula is within a few degrees of perpendicular to
the orbital plane of the central binary system - strong evidence that the
central close-binary system has played an important role in shaping the nebula.
Sp 1 is one of very few nebulae to have this link, between nebular symmetry
axis and binary plane, shown observationally.
View original:
http://arxiv.org/abs/1111.2860
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