Spectral trends in planetary nebulae: The roles of radiative and shock excitation

Details Spectral trends in planetary nebulae: The roles of radiative and shock excitation Spectral trends in planetary nebulae: The roles of radiative and shock excitation

Jun 1998

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998a%26as..130..465p&link_type=abstract

Astronomy and Astrophysics Supplement, v.130, p.465-476

Astronomy and Astrophysics

Astrophysics

11

Survey, Ism: Planetary Nebulae, Ism: Jets And Outflows, Shocks Waves

Scientific paper

We have investigated de-reddened spectral line ratios for some 538 planetary nebulae. As a result, it has proved possible to define comparative variations between differing transitions, evaluate the viability of radiative modeling for the generality of nebulae, and assess the importance of shocks in modifying low- excitation line strengths. Whilst most transitions are well represented in terms of radiative excitation, the [OI] lambda 6300 Angstroms line appears to be appreciably too strong in most of the present sample; a deviation which may arise through shock interaction between the primary outflow shell and enveloping superwind material. Comparison between shock modeling and line excesses also suggests that an appreciable proportion of [SII] lambda 6716/31 Angstroms emission may arise through shock excitation; a conclusion which, if confirmed, may have serious consequences for nebular density estimations. Some 14 nebulae are identified as likely shock candidates, whilst it is proposed that the majority of bipolar nebulae may also show spectral deviations associated with shock excitation. Line excesses for these latter sources are most consistent with shock velocities V_s ~ 80 => 100 km s(-1) ; values which are also comparable to observed wind velocities. Finally, sources containing FLIERs (\cite[Balick et al. 1993]{ba93}) are shown to be confined to highly specific spectral regimes; a result which permits us to identify three further possible FLIER sources, and propose characteristic line ratio diagnostics for the further discovery of such features.

Affiliated with

Also associated with

No associations

Rating

Spectral trends in planetary nebulae: The roles of radiative and shock excitation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Spectral trends in planetary nebulae: The roles of radiative and shock excitation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectral trends in planetary nebulae: The roles of radiative and shock excitation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1330332