Composition and Provenance

CosmicGrain separates current composition from stellar origin.

The current model tracks an evolving carbon fraction, allowing the surviving dust mass to be separated into carbonaceous and silicate components. The stellar source tag records whether a grain population was born through the SNII, AGB, or LRN channel.

These quantities should not be treated as synonyms. A source tag is a birth-history label; later sputtering, shocks, accretion, coagulation, and shattering can alter the grain population.

Recommended diagnostics

Report both

1. current dust mass grouped by stellar birth source; and
2. current grain size/composition conditioned on that source.

This makes it possible to ask how strongly the present-day dust population remembers its stellar origin after ISM processing.

Integrity check

For the implemented two-component composition bookkeeping, carbonaceous plus silicate dust mass should close to total surviving dust mass to numerical precision. A failure of that closure is a code/data-integrity problem rather than an astrophysical result.