{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2002:OHTMCU3S7MF2OX6THDFKTPDNES","short_pith_number":"pith:OHTMCU3S","canonical_record":{"source":{"id":"astro-ph/0204016","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2002-04-01T15:36:57Z","cross_cats_sorted":[],"title_canon_sha256":"c1d1a785258b0e12e3b64a0be43da9e9386415c2e8e55f099f2550506f83594a","abstract_canon_sha256":"a6a4d91ba267b7508ac5c4c63cd75098140496902112f6b16858a0828ea7aa4a"},"schema_version":"1.0"},"canonical_sha256":"71e6c15372fb0ba75fd338caa9bc6d24adf244096fe1a273acbf0ac6dc300086","source":{"kind":"arxiv","id":"astro-ph/0204016","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0204016","created_at":"2026-05-18T04:23:01Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0204016v1","created_at":"2026-05-18T04:23:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0204016","created_at":"2026-05-18T04:23:01Z"},{"alias_kind":"pith_short_12","alias_value":"OHTMCU3S7MF2","created_at":"2026-05-18T12:25:51Z"},{"alias_kind":"pith_short_16","alias_value":"OHTMCU3S7MF2OX6T","created_at":"2026-05-18T12:25:51Z"},{"alias_kind":"pith_short_8","alias_value":"OHTMCU3S","created_at":"2026-05-18T12:25:51Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2002:OHTMCU3S7MF2OX6THDFKTPDNES","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0204016","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2002-04-01T15:36:57Z","cross_cats_sorted":[],"title_canon_sha256":"c1d1a785258b0e12e3b64a0be43da9e9386415c2e8e55f099f2550506f83594a","abstract_canon_sha256":"a6a4d91ba267b7508ac5c4c63cd75098140496902112f6b16858a0828ea7aa4a"},"schema_version":"1.0"},"canonical_sha256":"71e6c15372fb0ba75fd338caa9bc6d24adf244096fe1a273acbf0ac6dc300086","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:23:01.218299Z","signature_b64":"Wlm8inTMUT1ScDCR5WiPlAhnTnoVRhkExzwDpNStF1iyjdKdgwvvm6edAhTYTnjwS/ywDspNCcsM2Hs1cyQAAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"71e6c15372fb0ba75fd338caa9bc6d24adf244096fe1a273acbf0ac6dc300086","last_reissued_at":"2026-05-18T04:23:01.217778Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:23:01.217778Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0204016","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T04:23:01Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1T/zqdUbUEYEzc8ttT+R7tSk7N6E0nq8qUCamI2Os7IpJY7cpOH5aprlhwblQmN7vJfFtuLfEein7XpEmQUkBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-04T08:32:57.287042Z"},"content_sha256":"eb1dd04dbe901bd372ace02ce971a3e144acf80c0c4c1188130b3332c5526d24","schema_version":"1.0","event_id":"sha256:eb1dd04dbe901bd372ace02ce971a3e144acf80c0c4c1188130b3332c5526d24"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2002:OHTMCU3S7MF2OX6THDFKTPDNES","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"N2H+ and C18O Depletion in a Cold Dark Cloud","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Charles J. Lada, Edwin A. Bergin, Joao Alves, Tracy L. Huard","submitted_at":"2002-04-01T15:36:57Z","abstract_excerpt":"We present sensitive, high angular resolution molecular-line observations of C18O and N2H+ toward the dark globule B68. We directly compare these data with the near-infrared extinction measurements of Alves, Lada, & Lada (2001) to derive the first evidence for the depletion of N2H+, and by inference N2, in a pre-stellar dark cloud. We also find widespread C18O depletion throughout the centrally condensed core of the B68 cloud. Specifically, we find the N2H+ emission to peak in a shell partially surrounding the peak of dust extinction. Moreover, the N2H+ peaks inside the much larger C18O deplet"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0204016","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T04:23:01Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GTPBRLLG+7OkYURtHf4hMNOX8CZjgaJp8yPIl60a6B9UDVQ6pW/kfeHsYrgpKDwch2bMgN/lFg8YkRHPgE2nCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-04T08:32:57.287396Z"},"content_sha256":"ec20d2fea408456efe5e847f1c21cae0b005700287a1b9b7bf051657138c75b2","schema_version":"1.0","event_id":"sha256:ec20d2fea408456efe5e847f1c21cae0b005700287a1b9b7bf051657138c75b2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/OHTMCU3S7MF2OX6THDFKTPDNES/bundle.json","state_url":"https://pith.science/pith/OHTMCU3S7MF2OX6THDFKTPDNES/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/OHTMCU3S7MF2OX6THDFKTPDNES/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-04T08:32:57Z","links":{"resolver":"https://pith.science/pith/OHTMCU3S7MF2OX6THDFKTPDNES","bundle":"https://pith.science/pith/OHTMCU3S7MF2OX6THDFKTPDNES/bundle.json","state":"https://pith.science/pith/OHTMCU3S7MF2OX6THDFKTPDNES/state.json","well_known_bundle":"https://pith.science/.well-known/pith/OHTMCU3S7MF2OX6THDFKTPDNES/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2002:OHTMCU3S7MF2OX6THDFKTPDNES","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":"a6a4d91ba267b7508ac5c4c63cd75098140496902112f6b16858a0828ea7aa4a","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2002-04-01T15:36:57Z","title_canon_sha256":"c1d1a785258b0e12e3b64a0be43da9e9386415c2e8e55f099f2550506f83594a"},"schema_version":"1.0","source":{"id":"astro-ph/0204016","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0204016","created_at":"2026-05-18T04:23:01Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0204016v1","created_at":"2026-05-18T04:23:01Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0204016","created_at":"2026-05-18T04:23:01Z"},{"alias_kind":"pith_short_12","alias_value":"OHTMCU3S7MF2","created_at":"2026-05-18T12:25:51Z"},{"alias_kind":"pith_short_16","alias_value":"OHTMCU3S7MF2OX6T","created_at":"2026-05-18T12:25:51Z"},{"alias_kind":"pith_short_8","alias_value":"OHTMCU3S","created_at":"2026-05-18T12:25:51Z"}],"graph_snapshots":[{"event_id":"sha256:ec20d2fea408456efe5e847f1c21cae0b005700287a1b9b7bf051657138c75b2","target":"graph","created_at":"2026-05-18T04:23:01Z","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 present sensitive, high angular resolution molecular-line observations of C18O and N2H+ toward the dark globule B68. We directly compare these data with the near-infrared extinction measurements of Alves, Lada, & Lada (2001) to derive the first evidence for the depletion of N2H+, and by inference N2, in a pre-stellar dark cloud. We also find widespread C18O depletion throughout the centrally condensed core of the B68 cloud. Specifically, we find the N2H+ emission to peak in a shell partially surrounding the peak of dust extinction. Moreover, the N2H+ peaks inside the much larger C18O deplet","authors_text":"Charles J. Lada, Edwin A. Bergin, Joao Alves, Tracy L. Huard","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2002-04-01T15:36:57Z","title":"N2H+ and C18O Depletion in a Cold Dark Cloud"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0204016","kind":"arxiv","version":1},"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:eb1dd04dbe901bd372ace02ce971a3e144acf80c0c4c1188130b3332c5526d24","target":"record","created_at":"2026-05-18T04:23:01Z","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":"a6a4d91ba267b7508ac5c4c63cd75098140496902112f6b16858a0828ea7aa4a","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2002-04-01T15:36:57Z","title_canon_sha256":"c1d1a785258b0e12e3b64a0be43da9e9386415c2e8e55f099f2550506f83594a"},"schema_version":"1.0","source":{"id":"astro-ph/0204016","kind":"arxiv","version":1}},"canonical_sha256":"71e6c15372fb0ba75fd338caa9bc6d24adf244096fe1a273acbf0ac6dc300086","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"71e6c15372fb0ba75fd338caa9bc6d24adf244096fe1a273acbf0ac6dc300086","first_computed_at":"2026-05-18T04:23:01.217778Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T04:23:01.217778Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Wlm8inTMUT1ScDCR5WiPlAhnTnoVRhkExzwDpNStF1iyjdKdgwvvm6edAhTYTnjwS/ywDspNCcsM2Hs1cyQAAw==","signature_status":"signed_v1","signed_at":"2026-05-18T04:23:01.218299Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0204016","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:eb1dd04dbe901bd372ace02ce971a3e144acf80c0c4c1188130b3332c5526d24","sha256:ec20d2fea408456efe5e847f1c21cae0b005700287a1b9b7bf051657138c75b2"],"state_sha256":"310afff77b414db18f850e3d4bf2849911dc7bab374c8823a3dd91d226606bc0"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"xfSwdW5bNen/F82J62vhNptZIlQE+il45kKsmPzvf022iZ/ojmm2FfBZGWFA7BZfLilnhUb2XxpEq0PWDqhGDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-04T08:32:57.289305Z","bundle_sha256":"627a11c68e20f9361702a54abb62b589b87d3a2f68a7d208cd74bf7827965474"}}