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eMail: icke@strw.LeidenUniv.nl

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Planetary Nebula Hydrodynamics:

Movies of Numerical Work

See the printed papers on my PN site, or browse in the electronic issues of Astronomy &Astrophysics. Caution Websurfers: these movies take quite a while to download! They are given in two formats: one low-quality at high compression, and one high quality that has about twice the size of the compressed version. For people with slower line connections, I have included a few movies of low-resolution simulations. All movies are in QuickTime format (Movie JPEG A-compression).

 

Case 2: Spherical Inflow

In these computations, the inflow from the central star is initially spherically symmetric around the white dwarf. The shape of the outer nebula is nonetheless comparable to what we saw in the simulations above. This is as expected from the analytic calculations, which predict that the outer shell of the nebula is shaped mostly by the density distribution in the "slow wind" with which the "fast wind" from the white dwarf collides.

Surrounding the star you will see a region where the flow appears very irregular while rushing outward. This is especially clear in the temperature maps. This is the phenomenon of supersonic turbulence. In principle it ought to be observable, but with current techniques this is not very easy.

Bipolar Nebula Shaped by a Spherical Supersonic Inflow

Click to enlarge
 Numerical computation of a spherical gas stream shooting into a slightly flattened atmosphere. In this composite image, red indicates the density, green the temperature, and blue the velocity of the gas. The image is cylindrically symmetric about the horizontal axis. The dying star, which is now a young white dwarf, is in the centre of the image. The image of Mz3 roughly corresponds to the red part. You can download a low-quality movie (1.7 Mb) or a high quality movie (4.2 Mb). Both movies are in QuickTime format.

Spherical Supersonic Inflow: density

Click to enlarge
 Numerical computation of a spherical gas stream shooting into a slightly flattened atmosphere. In this movie you see only the density of the gas. Red indicates high values, blue/purple is low. The image is cylindrically symmetric about the horizontal axis. You can download a low-quality movie (1.2 Mb) or a high quality movie (2.6 Mb). Both movies are in QuickTime format.

Spherical Supersonic Inflow: temperature

Click to enlarge
 Numerical computation of a spherical gas stream shooting into a slightly flattened atmosphere. In this movie you see only the temperature of the gas. Red indicates high values, blue/purple is low. The image is cylindrically symmetric about the horizontal axis. You can download a low-quality movie (2.8 Mb) or a high quality movie (7.4 Mb). Both movies are in QuickTime format. This type of temperature distribution ought to be observable in X-rays.

Spherical Supersonic Inflow: velocity

Click to enlarge
 Numerical computation of a spherical gas stream shooting into a slightly flattened atmosphere. In this movie you see only the velocity of the gas. Red indicates high values, blue/purple is low. Notice that the velocity drops abruptly beyond the red region: this is a shock wave. The image is cylindrically symmetric about the horizontal axis. You can download a low-quality movie (2.2 Mb) or a high quality movie (5.7 Mb). Both movies are in QuickTime format.

 

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