Bibcode
Cuesta, L.; Phillips, J. P.; Mampaso, A.
Referencia bibliográfica
Astronomy and Astrophysics, v.313, p.243-254
Fecha de publicación:
9
1996
Revista
Número de citas
10
Número de citas referidas
8
Descripción
High and low resolution spectroscopy, together with narrow and broad
band imaging have been acquired for the unusual outflow source NGC 7026.
We find evidence for appreciable changes in excitation, and a highly
variable emission structure, consistent in part with observed variations
in electron density. The mean electron density is found to be
n_e_=2.05x10^3^cm^-3^, whilst the mean extinction is A_v_=2.0mag. The
outflow kinematics match the optical structure in suggesting an
extremely complex flow, explainable in terms of four separate outflow
centres distributed at the extremities of an inner spheroidal shell.
Such features may constitute an advanced phase in the break-up of the
primary shell, and eventually lead to the formation of a more typical
bipolar outflow structure.