{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2002:KE2BUG6VVYHLB62YINQCGBXF36","short_pith_number":"pith:KE2BUG6V","canonical_record":{"source":{"id":"astro-ph/0201543","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2002-01-31T17:38:36Z","cross_cats_sorted":[],"title_canon_sha256":"ae5eb9f5e41280c1b17bd78e11f64ac7721bb75f654d2375a942431767f311c7","abstract_canon_sha256":"654fbe85eb9152049f8ef735b872fef3898b6dc5a8e4ee645bd1ae31aa3ae9e9"},"schema_version":"1.0"},"canonical_sha256":"51341a1bd5ae0eb0fb5843602306e5dfa9702bb20c94e84b7c2bc0f9383ae7d6","source":{"kind":"arxiv","id":"astro-ph/0201543","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0201543","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0201543v1","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0201543","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"pith_short_12","alias_value":"KE2BUG6VVYHL","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"pith_short_16","alias_value":"KE2BUG6VVYHLB62Y","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"pith_short_8","alias_value":"KE2BUG6V","created_at":"2026-07-04T14:11:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2002:KE2BUG6VVYHLB62YINQCGBXF36","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0201543","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2002-01-31T17:38:36Z","cross_cats_sorted":[],"title_canon_sha256":"ae5eb9f5e41280c1b17bd78e11f64ac7721bb75f654d2375a942431767f311c7","abstract_canon_sha256":"654fbe85eb9152049f8ef735b872fef3898b6dc5a8e4ee645bd1ae31aa3ae9e9"},"schema_version":"1.0"},"canonical_sha256":"51341a1bd5ae0eb0fb5843602306e5dfa9702bb20c94e84b7c2bc0f9383ae7d6","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T14:11:52.090837Z","signature_b64":"lxQWWiIxZNLfDwYGPXSJKzat5jQX7NWq7Yh7oX5yfehFS+zZAy7YeYDUqJzvRWbHhuWTrpFxdaQB9IYNyB10AQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"51341a1bd5ae0eb0fb5843602306e5dfa9702bb20c94e84b7c2bc0f9383ae7d6","last_reissued_at":"2026-07-04T14:11:52.090480Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T14:11:52.090480Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0201543","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":"2026-07-04T14:11:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"yUTnhNUrFxKIMLFbZwc1bkgzvV4IXmoJtA6f7ZgR03s+xvan1TMaaytb7M+OCM2ppvcHm/5So92o8Dc/gxaIAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-17T18:16:59.873952Z"},"content_sha256":"e10daa8a5ea03267b1b867eca549e0c9085dc786a65b1ce7a25ff76f1893287d","schema_version":"1.0","event_id":"sha256:e10daa8a5ea03267b1b867eca549e0c9085dc786a65b1ce7a25ff76f1893287d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2002:KE2BUG6VVYHLB62YINQCGBXF36","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Powerful obscured AGN in Chandra cluster fields","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A.C. Fabian, Cambridge), C.S. Crawford (Institute of Astronomy, P. Gandhi","submitted_at":"2002-01-31T17:38:36Z","abstract_excerpt":"Models for the origin of the hard X-ray background have suggested that sources with the most accretion activity lie hidden in highly obscured AGN. We report on our study of hard, serendipitous sources in the fields of Chandra clusters with fluxes close to the turn-over in the source-counts. These include two Type II quasars with measured X-ray luminosities >10^{45} ergs per second and column-densities >10^{23} cm^{-2}, one possibly being Compton-thick. Both show indications of redshifted Fe K\\alpha line emission. Radiative transfer modelling of the broad-band spectrum of a highly-magnified sou"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0201543","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/astro-ph/0201543/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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T14:11:52Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FjKdTWGKnhlSMwRvuSqO6it5UrSYuRhKEXRUnnGZpQD7eB5VeQK6bOOhdSySIPhxV4G10PrhylvUkaOpGSagAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-17T18:16:59.874344Z"},"content_sha256":"9f5322d1651263e427b0cbe0bef8cfba508afc28cb7765bc238051f763230247","schema_version":"1.0","event_id":"sha256:9f5322d1651263e427b0cbe0bef8cfba508afc28cb7765bc238051f763230247"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/KE2BUG6VVYHLB62YINQCGBXF36/bundle.json","state_url":"https://pith.science/pith/KE2BUG6VVYHLB62YINQCGBXF36/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/KE2BUG6VVYHLB62YINQCGBXF36/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":"2026-08-17T18:16:59Z","links":{"resolver":"https://pith.science/pith/KE2BUG6VVYHLB62YINQCGBXF36","bundle":"https://pith.science/pith/KE2BUG6VVYHLB62YINQCGBXF36/bundle.json","state":"https://pith.science/pith/KE2BUG6VVYHLB62YINQCGBXF36/state.json","well_known_bundle":"https://pith.science/.well-known/pith/KE2BUG6VVYHLB62YINQCGBXF36/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2002:KE2BUG6VVYHLB62YINQCGBXF36","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":"654fbe85eb9152049f8ef735b872fef3898b6dc5a8e4ee645bd1ae31aa3ae9e9","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2002-01-31T17:38:36Z","title_canon_sha256":"ae5eb9f5e41280c1b17bd78e11f64ac7721bb75f654d2375a942431767f311c7"},"schema_version":"1.0","source":{"id":"astro-ph/0201543","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0201543","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0201543v1","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0201543","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"pith_short_12","alias_value":"KE2BUG6VVYHL","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"pith_short_16","alias_value":"KE2BUG6VVYHLB62Y","created_at":"2026-07-04T14:11:52Z"},{"alias_kind":"pith_short_8","alias_value":"KE2BUG6V","created_at":"2026-07-04T14:11:52Z"}],"graph_snapshots":[{"event_id":"sha256:9f5322d1651263e427b0cbe0bef8cfba508afc28cb7765bc238051f763230247","target":"graph","created_at":"2026-07-04T14:11:52Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/astro-ph/0201543/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Models for the origin of the hard X-ray background have suggested that sources with the most accretion activity lie hidden in highly obscured AGN. We report on our study of hard, serendipitous sources in the fields of Chandra clusters with fluxes close to the turn-over in the source-counts. These include two Type II quasars with measured X-ray luminosities >10^{45} ergs per second and column-densities >10^{23} cm^{-2}, one possibly being Compton-thick. Both show indications of redshifted Fe K\\alpha line emission. Radiative transfer modelling of the broad-band spectrum of a highly-magnified sou","authors_text":"A.C. Fabian, Cambridge), C.S. Crawford (Institute of Astronomy, P. Gandhi","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2002-01-31T17:38:36Z","title":"Powerful obscured AGN in Chandra cluster fields"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0201543","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:e10daa8a5ea03267b1b867eca549e0c9085dc786a65b1ce7a25ff76f1893287d","target":"record","created_at":"2026-07-04T14:11:52Z","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":"654fbe85eb9152049f8ef735b872fef3898b6dc5a8e4ee645bd1ae31aa3ae9e9","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2002-01-31T17:38:36Z","title_canon_sha256":"ae5eb9f5e41280c1b17bd78e11f64ac7721bb75f654d2375a942431767f311c7"},"schema_version":"1.0","source":{"id":"astro-ph/0201543","kind":"arxiv","version":1}},"canonical_sha256":"51341a1bd5ae0eb0fb5843602306e5dfa9702bb20c94e84b7c2bc0f9383ae7d6","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"51341a1bd5ae0eb0fb5843602306e5dfa9702bb20c94e84b7c2bc0f9383ae7d6","first_computed_at":"2026-07-04T14:11:52.090480Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T14:11:52.090480Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"lxQWWiIxZNLfDwYGPXSJKzat5jQX7NWq7Yh7oX5yfehFS+zZAy7YeYDUqJzvRWbHhuWTrpFxdaQB9IYNyB10AQ==","signature_status":"signed_v1","signed_at":"2026-07-04T14:11:52.090837Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0201543","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e10daa8a5ea03267b1b867eca549e0c9085dc786a65b1ce7a25ff76f1893287d","sha256:9f5322d1651263e427b0cbe0bef8cfba508afc28cb7765bc238051f763230247"],"state_sha256":"d70721d26d45578820da9c590e47969e58a5b13122ba6c76305da432c7ec5043"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"I2exmwzHQN40hfi3rUlNJxKVmGfoOhd+N4jd0UHEaSCveJocCQfRqSEN2H+V/1QCRnMJ1raM8ra/1Rb2AofFCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-17T18:16:59.877698Z","bundle_sha256":"e2d2e085364cd555f6cebf6dd897f63c4ef47f595ec8b23da515fa5a3c1dc648"}}