{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2020:PFRLRELJ5P2WTUANQDY5PGD2DM","short_pith_number":"pith:PFRLRELJ","schema_version":"1.0","canonical_sha256":"7962b89169ebf569d00d80f1d7987a1b20b86d7a893f2a57af6fad65f513ea00","source":{"kind":"arxiv","id":"2005.03038","version":2},"attestation_state":"computed","paper":{"title":"On the origin of nitrogen at low metallicity","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"Alexander Heger, Arpita Roy, Lisa J. Kewley, Mark R. Krumholz, Michael A. Dopita, Ralph S. Sutherland","submitted_at":"2020-05-06T18:00:04Z","abstract_excerpt":"Understanding the evolution of the N/O ratio in the interstellar medium (ISM) of galaxies is essential if we are to complete our picture of the chemical evolution of galaxies at high redshift, since most observational calibrations of O/H implicitly depend upon the intrinsic N/O ratio. The observed N/O ratio, however, shows large scatter at low O/H, and is strongly dependent on galactic environment. We show that several heretofore unexplained features of the N/O distribution at low O/H can be explained by the N seen in metal-poor galaxies being mostly primary nitrogen that is returned to the IS"},"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":"2005.03038","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2020-05-06T18:00:04Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"dcf98a28362d26e7096d86d5f946cbdf41e7a5c54d92ea5927b5253bd9d3a0bd","abstract_canon_sha256":"ed4d2ab57f633a52ee1e7fe69078eb4f1d5d3be0d3f882208fadc79a4469ae1d"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:15:24.366910Z","signature_b64":"lvuyGEEFWrHE+yu4DoY7TtqVdKLR0+oQWQG2K2oidIIxOzpVJ67G/NTTRVwHrMBz0+hgijlz0DBZ14tZbDU6Dg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"7962b89169ebf569d00d80f1d7987a1b20b86d7a893f2a57af6fad65f513ea00","last_reissued_at":"2026-07-05T02:15:24.366414Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:15:24.366414Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"On the origin of nitrogen at low metallicity","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"Alexander Heger, Arpita Roy, Lisa J. Kewley, Mark R. Krumholz, Michael A. Dopita, Ralph S. Sutherland","submitted_at":"2020-05-06T18:00:04Z","abstract_excerpt":"Understanding the evolution of the N/O ratio in the interstellar medium (ISM) of galaxies is essential if we are to complete our picture of the chemical evolution of galaxies at high redshift, since most observational calibrations of O/H implicitly depend upon the intrinsic N/O ratio. The observed N/O ratio, however, shows large scatter at low O/H, and is strongly dependent on galactic environment. We show that several heretofore unexplained features of the N/O distribution at low O/H can be explained by the N seen in metal-poor galaxies being mostly primary nitrogen that is returned to the IS"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2005.03038","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2005.03038/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2005.03038","created_at":"2026-07-05T02:15:24.366473+00:00"},{"alias_kind":"arxiv_version","alias_value":"2005.03038v2","created_at":"2026-07-05T02:15:24.366473+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2005.03038","created_at":"2026-07-05T02:15:24.366473+00:00"},{"alias_kind":"pith_short_12","alias_value":"PFRLRELJ5P2W","created_at":"2026-07-05T02:15:24.366473+00:00"},{"alias_kind":"pith_short_16","alias_value":"PFRLRELJ5P2WTUAN","created_at":"2026-07-05T02:15:24.366473+00:00"},{"alias_kind":"pith_short_8","alias_value":"PFRLRELJ","created_at":"2026-07-05T02:15:24.366473+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/PFRLRELJ5P2WTUANQDY5PGD2DM","json":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM.json","graph_json":"https://pith.science/api/pith-number/PFRLRELJ5P2WTUANQDY5PGD2DM/graph.json","events_json":"https://pith.science/api/pith-number/PFRLRELJ5P2WTUANQDY5PGD2DM/events.json","paper":"https://pith.science/paper/PFRLRELJ"},"agent_actions":{"view_html":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM","download_json":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM.json","view_paper":"https://pith.science/paper/PFRLRELJ","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2005.03038&json=true","fetch_graph":"https://pith.science/api/pith-number/PFRLRELJ5P2WTUANQDY5PGD2DM/graph.json","fetch_events":"https://pith.science/api/pith-number/PFRLRELJ5P2WTUANQDY5PGD2DM/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM/action/timestamp_anchor","attest_storage":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM/action/storage_attestation","attest_author":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM/action/author_attestation","sign_citation":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM/action/citation_signature","submit_replication":"https://pith.science/pith/PFRLRELJ5P2WTUANQDY5PGD2DM/action/replication_record"}},"created_at":"2026-07-05T02:15:24.366473+00:00","updated_at":"2026-07-05T02:15:24.366473+00:00"}