Bibcode
DOI
Phillips, J. P.; Cuesta, L.
Referencia bibliográfica
The Astronomical Journal, Volume 117, Issue 2, pp. 974-980.
Fecha de publicación:
2
1999
Número de citas
8
Número de citas referidas
8
Descripción
We have acquired [O III] lambda5007, H I lambdalambda6563 and 4861, and
[S II] lambdalambda6717 and 6731 imaging of the bipolar outflow source
NGC 6445. As a result, we find that density is preferentially enhanced
within an interior optical/radio emission annulus and takes a maximum
value ~1.1x10^3 cm^-3. Visual extinction appears also to be enhanced
within this regime, taking values ~0.8 mag greater than for the
enveloping shell, a result that is shown to imply ratios A_v/N(H_2)
comparable to that of NGC 7027 and at least 4 times greater than for the
interstellar medium. Finally, we investigate the variation of excitation
through the projected nebular envelope. While the nucleus possesses
excitation properties consistent with normal (radiatively excited)
sources, it appears that line ratios toward the source periphery may
indicate the presence of appreciable shock activity.