Distance mapping technique and the 3-D structure of BD +30°3639

Images and high–resolution spectra from the literature are used in order to construct a 3–D model of BD +30 3639 using the morpho–kinematic code SHAPE. We find that two homologous expansion laws are needed for the [N II] and [O III] shell. A cylindrical velocity component is used to replicate the high–speed bipolar collimated outflows. We also present a new kinematic analysis technique called “distance mapping”. It uses the observed proper motion vectors and the 3–D velocity field to generate maps that can be used as a constraint to the morpho–kinematic modeling with SHAPE as well as improve the accuracy for distance determination. It is applied to BD+30 3639 using 178 internal proper motion vectors from Li et al. ([?]) and our 3–D velocity field to determine a distance of 1.52 ± 0.21 kpc. Finally, we find evidence for an interaction between the eastern part of nebula and the ambient H2 molecular gas.