Simulations =========== Specifications -------------- This page contains the specification of the simulations in AbacusSummit. We tabulate the simulations below. Simulation specifications are given a descriptive label, which is included in the simulation name: * **Base**: this is our standard size, 6912\ :sup:`3` particles in 2 Gpc/*h*. * **High**: A box with 6x better mass resolution, 6300\ :sup:`3` in 1 Gpc/*h*. * **Highbase**: A 1 Gpc/*h* box with the base mass resolution. * **Huge**: these are larger boxes run with 27x worse mass resolution. * **Hugebase**: Re-runs of some 2 Gpc/*h* boxes with the same 27x worse mass resolution. * **Fixedbase**: Simulations with the base mass resolution but fixed-amplitude initial conditions, 4096\ :sup:`3` in 1.18 Gpc/*h*. * **Small**: Simulations with base mass resolution but 1728\ :sup:`3` particles in 0.5 Gpc/*h*. Run-Time Products ----------------- Only a few of our simulations include the full timeslice output; we typically output only subsamples. The "Full Outputs" column in the simulations table below specifies the redshifts (if any) for which a simulation has full timeslices. This column refers to sets of redshifts using the following abbreviations: * **Full**: *z* = 3.0, 2.5, 2.0, 1.7, 1.4, 1.1, 0.8, 0.5, 0.4, 0.3, 0.2, 0.1 * **Partial**: *z* = 2.5, 1.4, 0.8, 0.2 * **Partial+HiZ**: Adds *z* = 3.0, 2.0 to the Partial list Subsamples of particles, with positions, velocities, ID numbers, and kernel density estimates, are typically provided at the same 12 redshifts as the Full list (see :doc:`data-products`). CompaSO group finding is run at these redshifts as well as 21 others (see :doc:`compaso`). .. note :: The 21 "secondary" redshifts are only approximate and may not match from simulation to simulation. We do not shorten the Abacus timestep to land exactly on these secondary redshifts as we do for the primary redshifts. Always use the redshift in the header, not the directory name. The huge and hugebase sims have fewer group finding and subsample epochs. Base sims and Huge sims have light-cone outputs; others do not. A base simulation typically produces about 10 TB of subsampled output, and each output slice is another 4 TB above that. Covariance (Small) Boxes ------------------------ We ran 2000 small simulations in 500 Mpc/*h* at the base mass resolution, intended for studies of covariance matrices in periodic boundary conditions. These have particle subsample outputs at *z* = 1.4, 1.1, 0.8, 0.5, and 0.2, as well as halo finding at all redshifts >0.2. However, about 15% of these simulations crashed due to some unresolved issue, almost certainly uncorrelated with any property of the large-scale structure in the simulation. Some of the crashed ones still produced usable outputs at higher redshifts. We have chosen to present the 1883 that yielded outputs at *z* = 1.1; 1643 of these reached *z* = 0.2. The numbering between ph3000 and ph4999 will be irregular. Simulations Table ----------------- The following is a complete listing of the AbacusSummit simulations. You can also download this table as a CSV file `here `_. The numbers in the "Cosm" column correspond to cosmologies in the :ref:`cosmologies:Cosmologies Table`. The "PPD" column is the number of particles-per-dimension. .. csv-table:: :file: ../Simulations/simulations.csv :header-rows: 1 :escape: ' Missing Data ------------ In the course of running AbacusSummit, a few rare instances of irreversible data loss occurred before the data could be archived. The resulting inhomogeneities in the data products presented by AbacusSummit are recorded here. - AbacusSummit_base_c103_ph000, for redshifts 0.8 and above, is missing all field particles and all halo RVs (but not halo PIDs). Consequently, the halo cleaning is not present at redshift 0.8 and above. - AbacusSummit_base_c004_ph003 is missing full (pack9) time slice outputs for redshifts 0.8 and 1.4. And, as a result, no time slice power spectra exist for those redshifts (AB power spectra exist as normal). - AbacusSummit_base_c163_ph000 is missing some light cone files; some step files are missing, and within step files, some ranks' outputs may be missing. The light cone should probably be treated as corrupt and unusable, although a manifest of all the files that survived to be merged into the ASDF data products is available under ``AbacusSummit_base_c163_ph000/lightcones/lcfiles.txt``. - AbacusSummit_base_c102_ph000 is missing all light cone step files except ``LightCone0`` for steps 991 and later. Within those step files, it is unknown if outputs from particular ranks are missing. The light cone should probably be treated as corrupt and unusable.