===== N-body models from Elena D'Onghia =====

Snapshots provided by Elena D'Onghia from her simulations in [[http://adsabs.harvard.edu/abs/2013ApJ...766...34D]], which have 100 million disk particles. Ask Jo Bovy to get these from a USB stick. The simulation and data consists of snapshots at 0 Myr (initial conditions), 250 Myr, and 1 Gyr (snap_000.hdf5, snap_005.hdf5, snap_020.hdf5).

The galaxy model consists of an Hernquist  halo with total mass of
9.5x10^11 Msun computed at a radius of 160 kpc. The halo is
simulated with a rigid potential. The concentration of the halo
is adopted to be c=9 for an Hernquist profile which is approximately like
c=12 for a NFW profile. The spin parameter of the halo is lambda=0.033.
This galaxy contains a live  stellar disk and a little live bulge that made
more stable the disk:

Disk:

The disk fraction is: Mdisk/Mhalo=0.04
The scale length is 2.5 kpc.
We introduced perturbers corotating with the stellar disk as softened
particles (the total number of perturbers is 1000 and each has a mass of
9.5x10^5 Msun so that the total mass of the perturbers  is ~ 9.5x10^8 Msun
which is ~2.5% of the total disk mass). In the run we fixed the softening
of the perturbes with  size of giant a molecular cloud:  ~100 pc.
In the initial setup the vertical thickness of the disk is setup z0=0.1 of
the scale length.
Number of particles in the disk= 100 millions.
In gadget snapshot stellar disk  particles are type 2.

Bulge:

The bulge fraction is: 0.01.
The size is 0.1 of the disk scale length.
Number of particles in the bulge is : 10 millions.
In gadget snapshot bulge particles are type 3.

The particles that mimic the perturbers are 1000 and in gadget are type 4.

Q parameter is initially set up to be larger than 1.3 at all radii.

==== Publication policy ====

If using these test data, please cite the Gaia Challenge wiki and  [[http://adsabs.harvard.edu/abs/2013ApJ...766...34D]].