DARWIN-1
FoF/Galaxy Catalog
Each HDF5 file snapshot contains the three subgroups: halo(FoF halos), sub(substructures, or galaxies), and unbound(gravitationally unbounded members within FoF halos). Note that sub and unbound share exactly the same structure.
| Field | Dimensions | Units | Description |
|---|---|---|---|
| nsub (halo) | 1 | Number of substructures in the given FoF halo | |
| halo_index (sub/unbound) | 1 | ID of the corresponding FoF halo (starting from 1) | |
| ndm | 1 | Number of dark matter (DM) particles | |
| nstar | 1 | Number of star particles | |
| nMBH | 1 | Number of massive black hole (MBH) particles | |
| ngas | 1 | Number of gas grids | |
| npall | 1 | ndm + nstar + nMBH + ngas | |
| mtot | 1 | Msun | Total mass |
| mdm | 1 | Msun | DM mass |
| mgas | 1 | Msun | Gas mass |
| mMBH | 1 | Msun | massive black hole (MBH) mass |
| mstar | 1 | Msun | Stellar mass |
| pos | 3 | cMpc | Center-of-mass position of all member particles |
| vel | 3 | km/s | Mass-weighted peculiar velocity |
Substructure
Each HDF5 snapshot file contains multiple (usually 400) subgroups of sub_[substructure ID]. Each sub_[substructure_ID] contains halo_index (ID of the corresponding FoF halo), and four subgroups: star (stellar particles), dm (dark matter particles), MBH (massive black hole particles), and gas (gas grid).
| Field | Dimensions | Units | Description |
|---|---|---|---|
| pos | 3 | cMpc | Position |
| vel | 3 | km/s | Peculiar velocity |
| mass | 1 | Msun | Mass |
| id (star/dm/MBH) | 1 | ID | |
| chem (star/gas) | 3 | Mass ratio of H, O, and Mg | |
| tp (star) / tbirth (MBH) | 1 | Gyr | The time when a given particle was formed |
| zp (star) / metal (gas) | 1 | Metallicity | |
| mass0 (star) | 1 | Msun | Initial stellar particle mass |
| angm (MBH) | 3 | cMpc km/s | Angular momentum |
| ang (MBH) | 3 | - | - |
| dmsmbh (MBH) | 1 | - | - |
| esave (MBH) | - | - | - |
| smag (MBH) | - | - | - |
| eps (MBH) | - | - | - |
| dx (gas) | 1 | Grid size | |
| density (gas) | 1 | Msun/cMpc3 | Gas density |
| temp (gas) | 1 | K | Gas temperature |
Since the number and total size of the entire substructure data at each snapshot are very large, we do not provide a direct method to download all of it. Instead, we recommend that you use the following procedure:
- Download the galaxy catalog and find a list of substructure IDs that you are interested in.
- Download download_sub.py and run:
python download_sub.py [snapshot id] [substructure ID].
DARWIN-2
N/A
DARWIN-3
N/A