SIMBAD references

We have acquired [O III] λ5007, H I λλ6563 and 4861, and [S II] λλ6717 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 ∼1.1x10³ 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(H₂) 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.