Vikram Visualizations

It is useful to create 3D and 2D images from 1-D simulations in order to better relate the simulation to real 3D objects as they are observed with telescopes.

Here 1D simulations from Vikram Dwarkadas are visualized, for details of the physics see:
Dwarkadas (2005) ApJ 630 892.

16 February 2006


22 February 2006:
Simple movies: density ; pseudo x-ray flux.

28 April 2006:
Simple movies - improved:
density (.mov)
frame-norm x-ray flux (.mov)
global-norm x-ray flux (.mov) , (.mpg)



X-ray intensity (approx.) projected to the sky
from the wrbub.1067 model.
Flux increases from blue to red.

An Example

The output of a 1D hydro simulation is given by a variety of scalars as a function of radius, the examples here are from the file wrbub.1067. This file can be read into IDL using the READCOL routine and the various scalars can be plotted in desired units, e.g., as done by:

To get a sense of the 3D nature of these 1D scalars, their values are used to weight the intensity of a spherically symmetric model created as a 3D cube of cells. These 3D values can be viewed as a "solid"-ish model in 3D ("thick"), cut in half to better show the radial structure. They can also be viewed as a 2D projection on the sky ("thin") - this is the way they'd be seen if viewed by a telescope (and assuming they are optically thin.)

Such images are presented below for the sample model file wrbub.1067 and were produced using the IDL procedure:

The several scalar values from the data file are plotted and imaged below; note that "pressure" looks to be proportional to "density * temperature" in this case.

The "X-ray flux" value is, as a very crude approximation, taken to be proportional to the density squared and is zero in regions where T is below 1.e6 K.


Scalar w/1D Plot 3D view, cut in half 2D projected intensity (blue to red)
Velocity(r)
Density(r)
Density(r)
version 2, 4/12/06
Temp(r)
Pressure(r)
X-ray_flux(r)
~ density^2 for T > 1.e+6
X-ray_flux(r)
version 2, 4/12/06
~ SQRT( density^2 / sqrt(Temp) ) for T > 1.e+6

dd@space.mit.edu