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Analysis

CosmicGrain's explicit dust particles make it possible to connect galaxy-scale dust budgets to the underlying grain population. Analysis should preserve the distinction between where a grain is, what it is now, and where it came from.

Core analysis rules

  1. Halo versus galaxy apertures — R200c is not interchangeable with a fixed physical ISM aperture.
  2. Gas-phase versus total metals — D/Z depends on which metal reservoir is used.
  3. Number versus mass weighting — grain-size and provenance distributions can look very different under the two weightings.
  4. Birth source versus present composition — the stellar source tag records provenance; later processing can change size and composition.
  5. Numerical validation versus scientific inference — a conserved whole-box budget does not imply a converged galaxy.

The shared analysis utilities should centralize periodic coordinates, halo centers, spherical-overdensity quantities, unit conversion, and target matching rather than duplicating these operations across plotting scripts.

  1. audit the complete snapshot;
  2. identify and center the target halo;
  3. measure or load M200c and R200c;
  4. define and record the galaxy/ISM aperture;
  5. compute baryonic, metal, and dust budgets;
  6. examine grain size, composition, and stellar provenance;
  7. construct spatial and radial diagnostics;
  8. derive extinction diagnostics where appropriate; and
  9. export controlled inputs for radiative-transfer calculations when needed.

Analysis topics