{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:7BCUPFYS5CKZ4J5YK4TBBPGLPR","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"d228cdcb9de766bc34b4773e786f54fee7d08f02db5efdc7995c23ac0956392d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-07-04T21:01:14Z","title_canon_sha256":"fbb6cfc84058306f9983e6ba323ea4ed84a6a9bfe90c5b7271d2712f5b2a13ed"},"schema_version":"1.0","source":{"id":"1107.0744","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1107.0744","created_at":"2026-05-18T03:33:14Z"},{"alias_kind":"arxiv_version","alias_value":"1107.0744v2","created_at":"2026-05-18T03:33:14Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1107.0744","created_at":"2026-05-18T03:33:14Z"},{"alias_kind":"pith_short_12","alias_value":"7BCUPFYS5CKZ","created_at":"2026-05-18T12:26:22Z"},{"alias_kind":"pith_short_16","alias_value":"7BCUPFYS5CKZ4J5Y","created_at":"2026-05-18T12:26:22Z"},{"alias_kind":"pith_short_8","alias_value":"7BCUPFYS","created_at":"2026-05-18T12:26:22Z"}],"graph_snapshots":[{"event_id":"sha256:65be38aa1678341d00341d77e724e92fde323a6b9d6c5855c2e590f98ff1057b","target":"graph","created_at":"2026-05-18T03:33:14Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \\times 10^{20}$ per cm$^{2}$; sightlines with lower HI column densities have high spin temperatures (median $T_s \\sim 1800$ K), indicating low fractions of the cold neutral medium (CNM), while sightlines with $N_{HI} \\ge 2 \\times 10^{20}$ per cm$^{2}$ have low spin temperatures (median $T_s \\sim 240$ K), implying high CNM fractions. The threshold for CNM formation is likely to arise due to inefficient self-shield","authors_text":"(2) CSIRO Astrophysics, (3) National Radio Astronomy Observatory, Australia, India, Nirupam Roy (3) ((1) National Centre for Radio Astrophysics, Nissim Kanekar (1), Robert Braun (2), Space Science, USA)","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-07-04T21:01:14Z","title":"An HI column density threshold for cold gas formation in the Galaxy"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1107.0744","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:81cec86ae216d0b141b118ea1c3bbb4a7600a379329afdce94f8d725720b59fc","target":"record","created_at":"2026-05-18T03:33:14Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"d228cdcb9de766bc34b4773e786f54fee7d08f02db5efdc7995c23ac0956392d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-07-04T21:01:14Z","title_canon_sha256":"fbb6cfc84058306f9983e6ba323ea4ed84a6a9bfe90c5b7271d2712f5b2a13ed"},"schema_version":"1.0","source":{"id":"1107.0744","kind":"arxiv","version":2}},"canonical_sha256":"f845479712e8959e27b8572610bccb7c7b86ec47529fa37a7440b05067a765fe","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f845479712e8959e27b8572610bccb7c7b86ec47529fa37a7440b05067a765fe","first_computed_at":"2026-05-18T03:33:14.381983Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:33:14.381983Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"3+wn1+Zchmq4jxPX1ZnoMC5qORRNajoSSKpQO4+s4t0CgrtfsRO2Jd6pCxIn3WM4tht8cJlu0qayf0oZ1LIoBw==","signature_status":"signed_v1","signed_at":"2026-05-18T03:33:14.382819Z","signed_message":"canonical_sha256_bytes"},"source_id":"1107.0744","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:81cec86ae216d0b141b118ea1c3bbb4a7600a379329afdce94f8d725720b59fc","sha256:65be38aa1678341d00341d77e724e92fde323a6b9d6c5855c2e590f98ff1057b"],"state_sha256":"2713c7af0e42d6edfe50e5ae896da9f0bf9381431d39402d3993927a6fbc1ecf"}