Millennium simulation in Celestia

[Vincent]

Martin,

The filiaments structure at large scale is quite visible with your last model that
represents galaxy clusters (first shot below).
It's clearly visible using your first model in which each point represents one single
galaxy (second shot below).
Ideally, we should get a smooth transition when zooming out from the "galaxies" model
to the "galaxy clusters" model. The problem is that the luminosity of point sprites increases
with the distance, whereas it should decrease...

[t00fri]

Yes, it has to look like Vincent's last image!

Fridger

[Cham]

Yes, it has to look like Vincent's last image!

Fridger

Fridger,

it is evident that you simply don't understand what it is all about.

Vincent has already said that the filament are visible in the first of his images (VERY large scale structure), while his second image is a MUCH smaller scale. The first picture **doesn't** have to look like the second !

The "small" cube (Vincent's second picture) has a size of about 280 MLY, while the cube shown in his first picture has a size of 3000 Mpc = 10 billions LY (approx).

The first image is showing the emergence of the cosmological principle (homogeneous distribution of matter at VERY large scale). And yet, we can clearly see some structures remaining (very large filaments and voids).

[Cham]

Some pictures to show the difference of scale involved here :

The small "pink" cube (sides of 280 MLY) at the center is a part of the Millennium simulation, while the larger "blue" blade (sides of 3000 Mpc) is from the VIRGO simulation. The "pink" cube is like Vincen't second picture (same model, actually, with a different color) :

cubeA.jpg

CubeB.jpg

CubeC.jpg

The pink dots are galaxies, while the blue fluffy sprites are clusters of galaxies.

[Vincent]

Yes, it has to look like Vincent's last image!

Fridger,

The model which corresponds to my above second shot is from Martin's first
simulation addon. I just removed the frame and changed the color and opacity.
You can get it here:
http://vincent.giangiulio.perso.sfr.fr/ ... iverse.zip

[Cham]

Multi-layers are great to show this kind of stuff in Celestia

Flying through the galactic clusters fog is fun !

multilayer.jpg

multilayer2.jpg

[ElChristou]

...Flying through the galactic clusters fog is fun !

BUT... ...it would be better with some kind of culling...

[Cham]

...Flying through the galactic clusters fog is fun !

BUT... ...it would be better with some kind of culling...

You mean a kind of depth effect (darker sprites with distance) ? Darker sprites in the background may be better looking, while inside the fog.

EDIT : Note to self : Some collisions to reproduce in 3D for Celestia :

http://www.haydenplanetarium.org/resour ... 33cmproret
http://www.ifa.hawaii.edu/~barnes/resea ... l#starform

With some help from the authors, I should be able to reproduce the object below, using sprites :


Other interesting web sites :

http://ifa.hawaii.edu/~barnes/saas-fee/mice_yrot.mpg
http://ifa.hawaii.edu/~barnes/transform.html

Amnd try this applet about galaxies collisions :
http://burro.cwru.edu/JavaLab/GalCrashWeb/step4.html

[Cham]

Here's a test model of a cosmological simulation from another research group :

cube.jpg

I just need to tweak the blobs size (proportional to the local density) and luminosity.

[Cham]

This box has 1 million of particles. VERY nice, in Celestia. A bit slow, though.

million.jpg

[chris]

This box has 1 million of particles. VERY nice, in Celestia. A bit slow, though.

million.jpg

I'd love to try this one--are you going to make it available?

--Chris

[Vincent]

This box has 1 million of particles. VERY nice, in Celestia. A bit slow, though.

I'd love to try this one--are you going to make it available?

So would I.

[Cham]

Yes, I'll publish it during the weekend. It's running very well on my computer, but it's a bit hard on the video card. I want to know how it would run on other computers too.

I'll also update the Millennium addon with a cube of sprites.

[Cham]

I've updated the first message of my addons thread to add a link to the new Klypin-Kravtsov cosmological models :

viewtopic.php?f=6&t=13555

[fsgregs]

When I load and view Cham's first simulation, as highlighted by Vincent on the prior page, an important question comes to mind. I would greatly appreciate your collective answer.

Here is the image from the simulation, with the Milky Way in the center. M31 and M33 are also visible:

Mill.jpg

The white dots behind the galaxies are the points of the simulation add-on.

If we were in a spacecraft at that particular position in space, looking at the Milky Way and the galactic points beyond it, would we see those galaxies as points of light as in the simulation, or is their magnitude too dim to pick up without a telescope? In other words, would the Millennium simulation in any form ... ever be a visually real event if we were able to locate far out in intergalactic space?

Thanks in advance for your advice

Frank