Evolution of planetary nebulae and their nuclei - Density of planetary nebulae and its evolutionary changes

Details Evolution of planetary nebulae and their nuclei - Density of planetary nebulae and its evolutionary changes Evolution of planetary nebulae and their nuclei - Density of planetary nebulae and its evolutionary changes

Oct 1976

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1976azh....53..961k&link_type=abstract

Astronomicheskii Zhurnal, vol. 53, Sept.-Oct. 1976, p. 961-974. In Russian.

Astronomy and Astrophysics

Astrophysics

4

Astronomical Models, Luminous Intensity, Planetary Nebulae, Radio Astronomy, Stellar Evolution, Astronomical Catalogs, Astrophysics, Electron Density (Concentration), H Ii Regions, Stellar Envelopes

Scientific paper

On the basis of data available in the literature, the relation between surface radio brightness at 6630 MHz and electron densities, determined from the forbidden doublets of Ar IV, Cl III, K V, O II and S II, is investigated for a large number of planetary nebulae. Although the empirical data are of low reliability so that the relation between density and surface brightness of planetary nebulae in hydrogen emission is rather diffuse, it still satisfies the hypothesis of unlimited expansion of nebulae at a constant initial mass. It is shown that at electron densities greater than 100,000 per cu cm planetary nebulae are partially ionized objects, consisting of an inner H II region surrounded by an envelope of neutral hydrogen. A model of a planetary nebulae is proposed which ties in with the model of Hromov and Kohoutek: A planetary nebula consists of a dense and bright main structure, emitting forbidden lines of O III, Ne III and K V, and a rarefied peripheral structure containing regions of luminescence in lowly excited O II, S II, Cl III, and others.

Affiliated with

Also associated with

No associations

Rating

Evolution of planetary nebulae and their nuclei - Density of planetary nebulae and its evolutionary changes 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 Evolution of planetary nebulae and their nuclei - Density of planetary nebulae and its evolutionary changes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of planetary nebulae and their nuclei - Density of planetary nebulae and its evolutionary changes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1568265