# A few collision animations...

Here are a few movies Marc did during his thesis work in order to check the working of the SPH code. Note that the choice is biased towards special cases whose outcome was sufficiently surprising to be worth of a check...

In the following table, M_sun and R_sun are the mass and radius of the sun. M_1 and M_2 are the (pre-collision) masses of the stars and R_1 and R_2 their radii. V_rel is the relative velocity at infinity, V_star=sqrt(2*G(M_1+M_2)/(R_1+R_2)) is the relative velocity the stars would have at contact  for V_rel=0.

Note:

The movies are encoded with Theora Vorbis (.ogg)

The reason for this format is because it reduces the size of the download (it's ~70% smaller than avi, mpg, mov etc).

Another important reason is that the Theora format is totally FREE (libre) (BSD), which means that everybody can play it without having to resort to privative codecs which, often, apart from requiring much larger files, are not for free.

If you are browsing with a recent version of firefox, the ogg movies will be automatically embedded in the page; otherwise you will have to download them and use, e.g. vlc. If your computer does not automatically play these files when you click on them, HERE you'll find the instructions to do it (for all plataforms, *BSD, GNU/Linux, Apple and windows)

In general, if you are not using firefox, the easiest is to install VLC

VLC Debian Ubuntu Linux (sudo apt-get install vlc)
VLC fedora / RHL Linux (install RPM Fusion and then su -c 'yum install vlc')
VLC openSUSE Linux
VLC Debian GNU/Linux
VLC Gentoo Linux
VLC MacOSX
VLC windows

M_1 in M_sun
M_2 in M_sun V_rel in V_star
d_min in (R_1+R_2)
.ogg animation(s)
0.500
0.500
0.05
0.30
density

0.500
0.500
0.05
0.80
density density density

1.200
1.000
3.74
0.07
density density

2.000
0.200
10.03
0.10
density therm_energy

2.000
2.000
0.77
0.00
density

2.000
2.000
0.77
0.10
density

2.000
2.000
4.60
0.00
density density

2.000
2.000
6.89
0.00
density

3.000
1.000
0.71
0.12
density

3.000
1.000
0.71
0.25
density

3.000
1.000
0.71
0.33
density

3.000
1.000
3.53
0.03
density

3.000
1.000
3.53
0.03
density temperature

3.000
1.000
7.06
0.24
density

3.000
1.000
21.18
0.25
density

5.000
1.000
0.06
0.10
density

5.000
1.000
0.06
0.20
density

5.000
1.000
0.06
0.30
density

5.000
1.000
0.06
0.40
density

5.000
1.000
0.06
0.43
density

7.000
1.700
3.68
0.00
density density temperature

14.745
2.500
5.32
0.15
density

19.321
0.909
4.87
0.00
density

19.321
1.000
14.77
0.20
density therm_energy

19.321
1.000
29.55
0.30
density

19.321
1.000
49.24
0.30
density

19.321
2.500
1.53
0.15
density