Sean Linden (UMass) and Chris Mihos (CWRU)
Animated Gifs
The "Coarse" animations use every 5th snapshot,
are smaller in size, and run faster. The "Fine" animations use
every snapshot, and are thus bigger in size, but run smoothly
and slowly. The "Long Term" snapshots show the long-term
behavior of particles in today's NE Plume.
Each animation pauses for a few seconds at the
current time.
Note: The animations are visualized with M101
fixed at the X,Y coordinate 0,0 at each time step. This is a
non-inertial frame, which makes the satellite orbital track
look a bit odd. Rest assured the dynamics are modeled
correctly!
| Animation | Coarse |
Fine |
Long Term |
| Interaction Sky View |
SKY_COARSE.gif |
SKY_FINE.gif |
|
| Interaction Orthogonal View |
SKYEDGE_COARSE.gif |
SKYEDGE_FINE.gif |
|
| Phase Space View |
PHASE_COARSE.gif |
PHASE_FINE.gif | |
| M101 Zoom View | SKYZOOM_COARSE.gif |
SKYZOOM_FINE.gif |
SKYZOOM_LONG.gif |
| M101 Zoom View, NE Plume tagged | SKYZOOMPLUME_COARSE.gif | SKYZOOMPLUME_FINE.gif | SKYZOOMPLUME_LONG.gif |
| M101 Edge View | M101EDGEZOOM_COARSE.gif |
M101EDGEZOOM_FINE.gif | |
| M101 Edge View, NE Plume tagged | M101EDGEZOOMPLUME_COARSE.gif | M101EDGEZOOMPLUME_FINE.gif | M101EDGEZOOMPLUME_LONG.gif |
Simulation Snapshots and Visualization Details
Selected snapshot files for the simulation can be found here,
with the snapshot
data format explained here. SNAP001 is the initial snapshot,
while SNAP201 is the snapshot of the system at the current (best
match) time.
| Snapshot File |
Simulation Time |
Scaled T-Tperi |
| SNAP001.gz |
0.0 |
-469 Myr |
| SNAP101.gz |
20.0 |
-129 Myr |
| SNAP121.gz |
24.0 |
-61 Myr |
| SNAP141.gz |
28.0 |
+7 Myr |
| SNAP161.gz |
32.0 |
+75 Myr |
| SNAP181.gz |
36.0 |
+143 Myr |
| SNAP201.gz |
40.0 |
+211 Myr |
| SNAP581.gz |
116.0 |
+1503 Myr |
The simulations are run using simulation units with the gravitational constant G = 1, and the mass and scale length of M101's disk are both also set = 1. To scale into physical units that match the M101 system, apply the following scale factors:
Note also that the animations and paper figures measure time relative to the moment of periapse, not the start of the simulation.
In the simulation snapshots, the XY plane is the orbital plane.
To rotate the simulation such that XY is M101's disk plane,
recenter on M101, then apply this transformation to the positions
and velocities:
x_m101 = -0.0872*x +
0.9962*y + 0.0000*z
y_m101 = 0.9623*x + 0.0842*y
+ 0.2588*z
z_m101 = 0.2578*x + 0.0226*y +
-0.9659*z
To rotate the simulation such that XY is the sky plane, first do
the previous rotation to M101's disk plane, then apply this
rotation (10 deg around X, 10 deg around Y):
x_sky = 0.9848*x_m101
+ 0.0000*y_m101 + 0.1736*z_m101
y_sky = -0.0301*x_m101 +
0.9848*y_m101 + 0.1710*z_m101
z_sky = -0.1710*x_m101 -
0.1736*y_m101 + 0.9698*z_m101
N-body Nitty Gritty (Parameter Files, etc)
buildgal parameter files: M101 and N5474
orbinit command line inputs: orbinit -mrat
8.0 -geom1 195.0 265.0 -geom2 150.0 100.0 -para -tp 24.0 -rp
1.0 -init
treecode parameter file: TREEPAR
