This table stores the numbers of the simulation snapshots along with the corresponding redshift and expansion factor of the universe.
|snapnum||int||time.epoch||snapshot number (in full snapshot sample)|
|aexp||float||time.epoch||expansion factor of the universe|
In principle, one can easily convert between redshift and expansion factor via the equation:
aexp = 1/(1+zred).
However, due to rounding-errors, the result can be slightly different from what is given in the table. We therefore provide both columns for convenience.
SELECT DISTINCT * FROM MDR1.Redshifts ORDER BY snapnum DESC
This query selects the complete redshifts-table. We use the
DISTINCT keyword here since this small table is replicated on each node and we want to avoid duplicate results.
For getting to know which redshifts/snapshots are available e.g. in the FOF-table, have a look at the AvailHalos table for the corresponding simulation.