{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2005:3KWOKFWRT4HUNNAU7374E67ERL","short_pith_number":"pith:3KWOKFWR","schema_version":"1.0","canonical_sha256":"daace516d19f0f46b414feffc27be48acb5754bbc8def974ca68871d382c50f6","source":{"kind":"arxiv","id":"astro-ph/0508381","version":2},"attestation_state":"computed","paper":{"title":"Descending from on high: Lyman series cascades and spin-kinetic temperature coupling in the 21 cm line","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Jonathan R. Pritchard, Steven R. Furlanetto (Caltech)","submitted_at":"2005-08-17T20:04:26Z","abstract_excerpt":"We examine the effect of Lyman continuum photons on the 21 cm background in the high-redshift universe. The brightness temperature of this transition is determined by the spin temperature T_s, which describes the relative populations of the singlet and triplet hyperfine states. Once the first luminous sources appear, T_s is set by the Wouthuysen-Field effect, in which Lyman-series photons mix the hyperfine levels. Here we consider coupling through n>2 Lyman photons. We first show that coupling (and heating) from scattering of Lyman-n photons is negligible, because they rapidly cascade to lower"},"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":"astro-ph/0508381","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2005-08-17T20:04:26Z","cross_cats_sorted":[],"title_canon_sha256":"f820441b612b8554de4bdfa2c065fab08272c8ae157e75e3390a10c627cb3579","abstract_canon_sha256":"32d6b4822c0e8a40c5db7daf55d2441b091b882383b16b2d6bdb6b4bdd49a16b"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T17:15:01.567073Z","signature_b64":"9v48WsO7K5Jb8aLRHTDzKauv0KqfsgnQU707jg+PNE+7JDFYwpGa/WAtvpw9BoKTdEDsBMaeSxLvGkLwStMdDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"daace516d19f0f46b414feffc27be48acb5754bbc8def974ca68871d382c50f6","last_reissued_at":"2026-07-04T17:15:01.566507Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T17:15:01.566507Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Descending from on high: Lyman series cascades and spin-kinetic temperature coupling in the 21 cm line","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Jonathan R. Pritchard, Steven R. Furlanetto (Caltech)","submitted_at":"2005-08-17T20:04:26Z","abstract_excerpt":"We examine the effect of Lyman continuum photons on the 21 cm background in the high-redshift universe. The brightness temperature of this transition is determined by the spin temperature T_s, which describes the relative populations of the singlet and triplet hyperfine states. Once the first luminous sources appear, T_s is set by the Wouthuysen-Field effect, in which Lyman-series photons mix the hyperfine levels. Here we consider coupling through n>2 Lyman photons. We first show that coupling (and heating) from scattering of Lyman-n photons is negligible, because they rapidly cascade to lower"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0508381","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/astro-ph/0508381/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":"astro-ph/0508381","created_at":"2026-07-04T17:15:01.566565+00:00"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0508381v2","created_at":"2026-07-04T17:15:01.566565+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0508381","created_at":"2026-07-04T17:15:01.566565+00:00"},{"alias_kind":"pith_short_12","alias_value":"3KWOKFWRT4HU","created_at":"2026-07-04T17:15:01.566565+00:00"},{"alias_kind":"pith_short_16","alias_value":"3KWOKFWRT4HUNNAU","created_at":"2026-07-04T17:15:01.566565+00:00"},{"alias_kind":"pith_short_8","alias_value":"3KWOKFWR","created_at":"2026-07-04T17:15:01.566565+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":3,"internal_anchor_count":2,"sample":[{"citing_arxiv_id":"2606.10005","citing_title":"On Cross-Correlating Line Intensity Maps from SPHEREx during Reionization","ref_index":50,"is_internal_anchor":true},{"citing_arxiv_id":"2504.17064","citing_title":"Imprints of energy injection by compact dark stars in the 21-cm signal","ref_index":66,"is_internal_anchor":true},{"citing_arxiv_id":"2604.17083","citing_title":"Dark ages bounds on non-accreting massive compact halo objects","ref_index":60,"is_internal_anchor":false}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL","json":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL.json","graph_json":"https://pith.science/api/pith-number/3KWOKFWRT4HUNNAU7374E67ERL/graph.json","events_json":"https://pith.science/api/pith-number/3KWOKFWRT4HUNNAU7374E67ERL/events.json","paper":"https://pith.science/paper/3KWOKFWR"},"agent_actions":{"view_html":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL","download_json":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL.json","view_paper":"https://pith.science/paper/3KWOKFWR","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=astro-ph/0508381&json=true","fetch_graph":"https://pith.science/api/pith-number/3KWOKFWRT4HUNNAU7374E67ERL/graph.json","fetch_events":"https://pith.science/api/pith-number/3KWOKFWRT4HUNNAU7374E67ERL/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL/action/timestamp_anchor","attest_storage":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL/action/storage_attestation","attest_author":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL/action/author_attestation","sign_citation":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL/action/citation_signature","submit_replication":"https://pith.science/pith/3KWOKFWRT4HUNNAU7374E67ERL/action/replication_record"}},"created_at":"2026-07-04T17:15:01.566565+00:00","updated_at":"2026-07-04T17:15:01.566565+00:00"}