Version 91 (modified by 11 years ago) ( diff ) | ,
---|
Planetary Nebula Library: Hydro Runs
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 – 10,000 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.
Update 10/7: |
Comparison of jet and clump in a low density ambient
t = 165 years
Jet / Clump Radius | 500 AU |
Jet / Clump Density | 40,000 cm-3 |
Jet / Temperature | 10 K |
Ambient Density | .01 cm-3 |
Ambient Temperature | 1 K |
Clump | Jet | |
---|---|---|
Radius | 500 AU | 500AU |
Density | 40,000 cm-3 | 40,000 cm-3 |
Temperature | 10 K | 10 K |
Speed | 50 km/s | |
Start Time | 0yrs | 990yrs |
Ambient Density | 1 cm-3 |
Ambient Temperature | 1 K |
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:
- describes the contrast in density of the torus from the pole to the equator.
- 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 ( | ).7 |
Torus Beta ( | ).8 |
(See Ruka's PN Page for MHD models.)
Toroidal + Stratified Ambient
Jet
Jet Velocity = 100 km/s | Jet Velocity = 200 km/s | Jet Velocity = 300 km/s | Velocity COmparison |
---|---|---|---|
movie | movie | movie | |
movie | movie | movie |
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 | *Note time difference!* |
movie | movie | movie |
Changes to Standard Parameters | |
---|---|
Jet Temperature | 10,000 K |
Ambient Density | 1,000 cm-3 |
Jet Velocity = 300 km/s |
---|
Clump
Clump Velocity = 100 km/s | Clump Velocity = 200 km/s | Clump Velocity = 300 km/s | Velocity Comparison |
---|---|---|---|
movie | movie | movie | |
movie | movie | movie |
Constant Ambient
Jet
Changes to Standard Parameters | |
---|---|
Ambient Density | 1 cm-3 |
Jet Velocity = 100 km/s | Jet Velocity = 200 km/s | Jet Velocity = 300 km/s | Velocity Comparison |
---|---|---|---|