{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2009:QXNB7BKX7T34N77GPJXH2IDRCK","short_pith_number":"pith:QXNB7BKX","schema_version":"1.0","canonical_sha256":"85da1f8557fcf7c6ffe67a6e7d2071129daf337fd74a6386dad6ef306fe24184","source":{"kind":"arxiv","id":"0902.2748","version":1},"attestation_state":"computed","paper":{"title":"The ionization fraction gradient across the Horsehead edge: An archetype for molecular clouds","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"(2) IRAM, (3) LERMA, (4) LAOG, (5) Luth), J. Le Bourlot (5) ((1) Cab-Csic, J. Pety (2), J.R. Goicoechea (1), M. Gerin (3), P. Hily-Blant (4)","submitted_at":"2009-02-16T18:33:25Z","abstract_excerpt":"The ionization fraction plays a key role in the chemistry and dynamics of molecular clouds. We study the H13CO+, DCO+ and HOC+ line emission towards the Horsehead, from the shielded core to the UV irradiated cloud edge, i.e., the Photodissociation Region (PDR), as a template to investigate the ionization fraction gradient in molecular clouds. We analyze a PdBI map of the H13CO+ J=1-0 line, complemented with IRAM-30m H13CO+ and DCO+ higher-J line maps and new HOC+ and CO+ observations. We compare self-consistently the observed spatial distribution and line intensities with detailed depth-depend"},"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":"0902.2748","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2009-02-16T18:33:25Z","cross_cats_sorted":[],"title_canon_sha256":"4f133c2bee3c62a9ed38026e1fed73029d8760a6f61547c434601c9527699e49","abstract_canon_sha256":"963b544d7b1864dee721e1be74b15d77ca79be2249c4a96f29e5c9e1412ca1cd"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:14:47.532595Z","signature_b64":"bqR36smqXpXIRfSgYmUhYGPV/0jtme0F6t3sq28BFzRQq13VHfJ5xdvDj6MefprxEFK4UIOqb835r6j+gnuFDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"85da1f8557fcf7c6ffe67a6e7d2071129daf337fd74a6386dad6ef306fe24184","last_reissued_at":"2026-05-18T02:14:47.531899Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:14:47.531899Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"The ionization fraction gradient across the Horsehead edge: An archetype for molecular clouds","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"(2) IRAM, (3) LERMA, (4) LAOG, (5) Luth), J. Le Bourlot (5) ((1) Cab-Csic, J. Pety (2), J.R. Goicoechea (1), M. Gerin (3), P. Hily-Blant (4)","submitted_at":"2009-02-16T18:33:25Z","abstract_excerpt":"The ionization fraction plays a key role in the chemistry and dynamics of molecular clouds. We study the H13CO+, DCO+ and HOC+ line emission towards the Horsehead, from the shielded core to the UV irradiated cloud edge, i.e., the Photodissociation Region (PDR), as a template to investigate the ionization fraction gradient in molecular clouds. We analyze a PdBI map of the H13CO+ J=1-0 line, complemented with IRAM-30m H13CO+ and DCO+ higher-J line maps and new HOC+ and CO+ observations. We compare self-consistently the observed spatial distribution and line intensities with detailed depth-depend"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0902.2748","kind":"arxiv","version":1},"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":"0902.2748","created_at":"2026-05-18T02:14:47.532012+00:00"},{"alias_kind":"arxiv_version","alias_value":"0902.2748v1","created_at":"2026-05-18T02:14:47.532012+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0902.2748","created_at":"2026-05-18T02:14:47.532012+00:00"},{"alias_kind":"pith_short_12","alias_value":"QXNB7BKX7T34","created_at":"2026-05-18T12:26:01.383474+00:00"},{"alias_kind":"pith_short_16","alias_value":"QXNB7BKX7T34N77G","created_at":"2026-05-18T12:26:01.383474+00:00"},{"alias_kind":"pith_short_8","alias_value":"QXNB7BKX","created_at":"2026-05-18T12:26:01.383474+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":3,"internal_anchor_count":3,"sample":[{"citing_arxiv_id":"2607.07489","citing_title":"Chemical diversity of dense cores in Orion B: The role of the environment","ref_index":56,"is_internal_anchor":true},{"citing_arxiv_id":"2606.23802","citing_title":"Characterising magnetic fields at the onset of star cluster formation: From giant molecular clouds to infrared dark clumps","ref_index":100,"is_internal_anchor":true},{"citing_arxiv_id":"2606.27110","citing_title":"Probing Anomalous Microwave Emission with the Square Kilometre Array","ref_index":120,"is_internal_anchor":true}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK","json":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK.json","graph_json":"https://pith.science/api/pith-number/QXNB7BKX7T34N77GPJXH2IDRCK/graph.json","events_json":"https://pith.science/api/pith-number/QXNB7BKX7T34N77GPJXH2IDRCK/events.json","paper":"https://pith.science/paper/QXNB7BKX"},"agent_actions":{"view_html":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK","download_json":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK.json","view_paper":"https://pith.science/paper/QXNB7BKX","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=0902.2748&json=true","fetch_graph":"https://pith.science/api/pith-number/QXNB7BKX7T34N77GPJXH2IDRCK/graph.json","fetch_events":"https://pith.science/api/pith-number/QXNB7BKX7T34N77GPJXH2IDRCK/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK/action/timestamp_anchor","attest_storage":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK/action/storage_attestation","attest_author":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK/action/author_attestation","sign_citation":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK/action/citation_signature","submit_replication":"https://pith.science/pith/QXNB7BKX7T34N77GPJXH2IDRCK/action/replication_record"}},"created_at":"2026-05-18T02:14:47.532012+00:00","updated_at":"2026-05-18T02:14:47.532012+00:00"}