{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2012:2ZW7MYI547WYVRY4WFVUHQLVFF","short_pith_number":"pith:2ZW7MYI5","schema_version":"1.0","canonical_sha256":"d66df6611de7ed8ac71cb16b43c17529676e91faa310cfbe31950f141fec2f7c","source":{"kind":"arxiv","id":"1210.0338","version":2},"attestation_state":"computed","paper":{"title":"Star formation history of resolved galaxies. I. The Method","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"David Bersier, Emma E. Small, Liverpool John Moores University, Maurizio Salaris (Astrophysics Research Institute, UK)","submitted_at":"2012-10-01T10:18:49Z","abstract_excerpt":"We present a new method to determine the star formation and metal enrichment histories of any resolved stellar system. This method is based on the fact that any observed star in a colour-magnitude diagram will have a certain probability of being associated with an isochrone characterised by an age t and metallicity [Fe/H] (i.e. to have formed at the time and with the metallicity of that isochrone). We formulate this as a maximum likelihood problem that is then solved with a genetic algorithm. We test the method with synthetic simple and complex stellar populations. We also present tests using "},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1210.0338","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2012-10-01T10:18:49Z","cross_cats_sorted":[],"title_canon_sha256":"f6dac6579b14634bfd1b4c0ab8276e1264c46149b7c10d51a9639c905c8693f8","abstract_canon_sha256":"5264e1d19f6035e26b13ae925f5e50084fec77f51fb784ffdb64f350b7efcd48"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:54:12.193675Z","signature_b64":"lAr/dp0ewGcT8XArzFyluwHT1HUE6fTC38NM8fCi9c3Jq5swbWknXNf9V0X6Aba5dX4jf7NqkJhGW6B/S7H6DQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d66df6611de7ed8ac71cb16b43c17529676e91faa310cfbe31950f141fec2f7c","last_reissued_at":"2026-05-18T01:54:12.193078Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:54:12.193078Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Star formation history of resolved galaxies. I. The Method","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"David Bersier, Emma E. Small, Liverpool John Moores University, Maurizio Salaris (Astrophysics Research Institute, UK)","submitted_at":"2012-10-01T10:18:49Z","abstract_excerpt":"We present a new method to determine the star formation and metal enrichment histories of any resolved stellar system. This method is based on the fact that any observed star in a colour-magnitude diagram will have a certain probability of being associated with an isochrone characterised by an age t and metallicity [Fe/H] (i.e. to have formed at the time and with the metallicity of that isochrone). We formulate this as a maximum likelihood problem that is then solved with a genetic algorithm. We test the method with synthetic simple and complex stellar populations. We also present tests using "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1210.0338","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"1210.0338","created_at":"2026-05-18T01:54:12.193155+00:00"},{"alias_kind":"arxiv_version","alias_value":"1210.0338v2","created_at":"2026-05-18T01:54:12.193155+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1210.0338","created_at":"2026-05-18T01:54:12.193155+00:00"},{"alias_kind":"pith_short_12","alias_value":"2ZW7MYI547WY","created_at":"2026-05-18T12:26:50.516681+00:00"},{"alias_kind":"pith_short_16","alias_value":"2ZW7MYI547WYVRY4","created_at":"2026-05-18T12:26:50.516681+00:00"},{"alias_kind":"pith_short_8","alias_value":"2ZW7MYI5","created_at":"2026-05-18T12:26:50.516681+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF","json":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF.json","graph_json":"https://pith.science/api/pith-number/2ZW7MYI547WYVRY4WFVUHQLVFF/graph.json","events_json":"https://pith.science/api/pith-number/2ZW7MYI547WYVRY4WFVUHQLVFF/events.json","paper":"https://pith.science/paper/2ZW7MYI5"},"agent_actions":{"view_html":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF","download_json":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF.json","view_paper":"https://pith.science/paper/2ZW7MYI5","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1210.0338&json=true","fetch_graph":"https://pith.science/api/pith-number/2ZW7MYI547WYVRY4WFVUHQLVFF/graph.json","fetch_events":"https://pith.science/api/pith-number/2ZW7MYI547WYVRY4WFVUHQLVFF/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF/action/timestamp_anchor","attest_storage":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF/action/storage_attestation","attest_author":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF/action/author_attestation","sign_citation":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF/action/citation_signature","submit_replication":"https://pith.science/pith/2ZW7MYI547WYVRY4WFVUHQLVFF/action/replication_record"}},"created_at":"2026-05-18T01:54:12.193155+00:00","updated_at":"2026-05-18T01:54:12.193155+00:00"}