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Planetary Nebula Library: Hydro Runs

Update 10/9:

Comparison of high and low resolution

Update 10/3:

Current summary of results:
Up to this point we have focused on changing the following parameters (within the ranges stated in parentheses) for a jet traveling in a stratified and toroidal ambient medium:

• Velocity of the jet (100 – 500 km/s)
• Temperature of the jet (10 – 1,000,000 K)
• Torus alpha (.3 - .9)
• Torus beta (.2 - .8)
• Ambient density (400 – 1,000 cm^-3)
• Ambient temperature (1 – 100 K)

We have also tested a jet in a constant ambient density, with a decreased ambient density and a clump in a normal stratified and toroidal ambient.

What works: Through these runs we have found that the most significant changes occur when the velocity and temperature of the jet are changed. Moderate changes are made by changing the ambient density. The shape of the ablation flow is most significantly affected by an increase in jet temperature. We see a widening of the central region that at higher speeds becomes more cylindrical, while a jet with a temperature of 10K seems to converge more to a point at the head of the jet.

What works a little: Changes in the ambient density seems to affect some of the inner shape as well as affecting the instabilities.

What doesn’t work: Changes in torus alpha and beta only slightly change the bottom of the lobe (seeming to move it “up”) but do not change the shape of the lobe and changes in ambient temperature do practically nothing in changing the shape, density, or temperature distribution of the lobe.

Go ​here to find a list of changes that were made today.

Reason for Library

Here we explore a variety of possible parameters and environments that can shape planetary nebulae, presented in various forms. This library will record a number of combinations of different density backgrounds and types of flows and also any parameter changes within those different combinations. The environments and flow structures are listed below.

Environments:

• Constant Ambient: The surrounding density is initially constant.
• Stratified Ambient: The surrounding density falls off as 1/r².
• Toroidal Ambient: The surrounding density decays from the equator to the pole as defined in ​Frank & Mellema, 1994 Apj by the following variables:
  • \alpha_{t} describes the contrast in density of the torus from the pole to the equator.
  • \beta_{t} describes how elliptical or spherical the torus is. Small values coincide with a more elliptical torus while values closer to 1 indicate a more spherical torus.

Flow Structures:

• Clump: A spherical cloud of gas.
• Jet: A constant stream of gas.
• Diverging Wind: A constant stream of gas that sweeps an arc in the surrounding medium.

Below are the standard parameters used in each run. Any changes to these parameters will be noted in the table preceding the image table.

Standard Parameters
Jet Radius	500 AU
Jet Density	40,000 cm-3
Jet Temperature	10 K
Ambient Density	400 cm-3
Ambient Temperature	1 K
Torus Alpha (\alpha_{t})	.7
Torus Beta (\beta_{t})	.8

(See ​Ruka's PN Page for MHD models.)

Toroidal + Stratified Ambient

Jet

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Jet Velocity = 100 km/s	Jet Velocity = 200 km/s	Jet Velocity = 300 km/s	Velocity COmparison
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Changes to Standard Parameters
Jet Temperature	10,000 K

Jet Velocity = 100 km/s	Jet Velocity = 200 km/s	Jet Velocity = 300 km/s	Jet Velocity = 800 km/s
​movie	​movie	​movie	​movie *Note time difference!*
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Changes to Standard Parameters
Jet Temperature	1,000,000 K

Jet Velocity = 300 km/s
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Changes to Standard Parameters
Jet Temperature	10,000 K
Ambient Density	1,000 cm-3

Jet Velocity = 300 km/s
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Clump

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Clump Velocity = 100 km/s	Clump Velocity = 200 km/s	Clump Velocity = 300 km/s	Velocity Comparison
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Constant Ambient

All constant ambient density models have the following change to the standard parameters listed at the top of this page.

Changes to Standard Parameters
Ambient Density	1 cm-3

Jet

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Jet Velocity = 100 km/s	Jet Velocity = 200 km/s	Jet Velocity = 300 km/s	Velocity Comparison
​movie	​movie	​movie
​movie	​movie	​movie

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Changes to Standard Parameters
Jet Temperature	10,000 K

Jet Velocity = 100 km/s	Jet Velocity = 200 km/s	Jet Velocity = 300 km/s	Velocity Comparison
​movie
​movie

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Clump & Jet

	Clump	Jet
Radius	500 AU	500AU
Density	40,000 cm-3	40,000 cm-3
Temperature	10 K	10,000 K
Speed	50 km/s	200 km/s
Start Time	0yrs	990yrs

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