Introduction
This is the mock galaxy catalogs in Horizon Run 4 simulation (Kim, Park, L'Huillier & Hong 2015) created by the most bound halo particle(MBP)-galaxy correspondence model (Hong, Park & Kim 2016).
Horizon Run 4 simulation is a cosmological N-body simulation with the following properties:
- Box size: (3,150 cMpc/h)3
- Number of matter particles: 6,3003
- Cosmology: WMAP 5-year ΛCDM cosmology;
(Ωm, ΩΛ, h, σ8, ns) = (0.26, 0.74, 0.72, 0.79, 0.96)
Data
The entire simulation box is split with 64 equal-volume subsamples.
Each data file has a name as z[redshift]_[xbin][ybin][zbin].hdf5,
which contains a subsample with 787.5×xbin ≤ x/(cMpc/h) ≤ 787.5×(xbin+1), 787.5×ybin ≤ y/(cMpc/h) ≤ 787.5×(ybin+1), 787.5×zbin ≤ z/(cMpc/h) ≤ 787.5×(zbin+1).
Each data file is written as HDF5 file format containing the following properties:
- x, y, z: Position in comoving coordinate (cMpc/h)
- vx, vy, vz: Peculiar velocity (km/s)
- mass: Mass of the galaxy (Msun/h; see the warning below)
Snapshot: z = 0
Snapshot: z = 0.5
See the warning below.
Snapshot: z = 1
See the warning below.
Warnings
Note that the mass of the galaxy is not the FoF halo mass, subhalo mass, or the stellar mass.
It is a rather artificial mass-like quantity that you can use as a proxy of galaxy luminosity in a way that brighter galaxies have higher mass.
A typical example of using mass is to make a volume-limited galaxy sample up to a certain brightness threshold.
- First, calculate the number density of galaxies with the same brightness threshold from the observation.
- Next, find the minimum mass threshold from the mock galaxy catalog that gives the same galaxy number density.
- Then select the galaxies whose mass is above the given threshold to make the mock volume-limited galaxy sample.
However, note that the above example assumes that the both completeness of observation up to a given brightness threshold and the correlation between the given types of brightness and halo/stellar mass are very high.
The given mock galaxy catalog is tuned so that its two-point correlation function at z = 0 agrees well with the SDSS Main Galaxy Sample in scales between 0.1 Mpc/h -- 100 Mpc/h.
However, it may not fully guarantee the good agreement of spatial distribution at higher z (e.g., z > 0.5).
If you have questions on the above issues, please contact Dr. Sungwook E. Hong.
References
Please cite the following references if you use the above mock galaxy catalog.
- Kim, J., Park, C., L'Huillier, B., & Hong, S.E. 2015, JKAS, 48, 213
- Hong, S.E., Park, C. & Kim, J. 2016, ApJ, 823, 103
If you have a question, please contact Dr. Sungwook E. Hong.
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