{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2001:N2WDYSIU4I6IFRGQQZRJBJ62RB","short_pith_number":"pith:N2WDYSIU","canonical_record":{"source":{"id":"astro-ph/0109172","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2001-09-11T11:43:27Z","cross_cats_sorted":[],"title_canon_sha256":"d8f221822405e97cca96938cd6aad96be0bed67c753584d0176317834b2a5dcc","abstract_canon_sha256":"90c262e218f07e42dcfc6ad0f27c20ce890bb885e0fb6bb21069732510274df2"},"schema_version":"1.0"},"canonical_sha256":"6eac3c4914e23c82c4d0866290a7da8869805d91382b0181b737304ea771e53e","source":{"kind":"arxiv","id":"astro-ph/0109172","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0109172","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0109172v1","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0109172","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"pith_short_12","alias_value":"N2WDYSIU4I6I","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"pith_short_16","alias_value":"N2WDYSIU4I6IFRGQ","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"pith_short_8","alias_value":"N2WDYSIU","created_at":"2026-07-04T14:11:28Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2001:N2WDYSIU4I6IFRGQQZRJBJ62RB","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0109172","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2001-09-11T11:43:27Z","cross_cats_sorted":[],"title_canon_sha256":"d8f221822405e97cca96938cd6aad96be0bed67c753584d0176317834b2a5dcc","abstract_canon_sha256":"90c262e218f07e42dcfc6ad0f27c20ce890bb885e0fb6bb21069732510274df2"},"schema_version":"1.0"},"canonical_sha256":"6eac3c4914e23c82c4d0866290a7da8869805d91382b0181b737304ea771e53e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T14:11:28.125931Z","signature_b64":"xAd0XIEQ+4b932EDgY61gRHmfEsE8dEbwOrsA9YXUkrZKtsPzjXb+FQgb3F7W1PHiGXYOZRFQ+HMj00tI+1yBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"6eac3c4914e23c82c4d0866290a7da8869805d91382b0181b737304ea771e53e","last_reissued_at":"2026-07-04T14:11:28.125403Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T14:11:28.125403Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0109172","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":"2026-07-04T14:11:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QbO/ZFJY8J1926VS1lbyFw3Nai6dRJFsYB6nwjek09Vn5uSoonndqMu/A4m7ImDqUhJAVC9q4+2lJNrxQ8bTAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T13:28:15.234952Z"},"content_sha256":"ccb1accea52d63dc77451f07b1b9452be7d4235f11552641d0706ab31d14d1f1","schema_version":"1.0","event_id":"sha256:ccb1accea52d63dc77451f07b1b9452be7d4235f11552641d0706ab31d14d1f1"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2001:N2WDYSIU4I6IFRGQQZRJBJ62RB","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Exploring the Early Universe with XMM-Newton","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"G. Hasinger, I. Lehmann, M. Schmidt, S.S. Murray","submitted_at":"2001-09-11T11:43:27Z","abstract_excerpt":"The question of the X-ray background has been largely settled over the last 10 years using the ROSAT satellite. About 70-80 % of the soft X-ray background was resolved into discrete sources, which are mainly X-ray and optically unobscured AGNs (Quasars, Sy1). Furthermore we found already several obscured AGNs in deep ROSAT surveys, which are predicted by the population synthesis models for the X-ray background, based on the unified AGN schemes. However, deep X-ray surveys using Chandra} and XMM-Newton allow to test the reliability of these models, which seem to be still far from unique. Recent"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0109172","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/0109172/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":"2026-07-04T14:11:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"dG0Ll1AnRvZiw6VdzQ0m6cwdUgH5vXE1exuiTCmqNr64J4kfJr6Yarfx1vh8ey3Jc4W5h1NUUxpCmQkqzW5BBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T13:28:15.235349Z"},"content_sha256":"b1d8e5c9617e9b05803774d19461bf963377ebecbe06519b0da89c7d49f0af15","schema_version":"1.0","event_id":"sha256:b1d8e5c9617e9b05803774d19461bf963377ebecbe06519b0da89c7d49f0af15"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB/bundle.json","state_url":"https://pith.science/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB/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":"2026-07-07T13:28:15Z","links":{"resolver":"https://pith.science/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB","bundle":"https://pith.science/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB/bundle.json","state":"https://pith.science/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB/state.json","well_known_bundle":"https://pith.science/.well-known/pith/N2WDYSIU4I6IFRGQQZRJBJ62RB/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2001:N2WDYSIU4I6IFRGQQZRJBJ62RB","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":"90c262e218f07e42dcfc6ad0f27c20ce890bb885e0fb6bb21069732510274df2","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2001-09-11T11:43:27Z","title_canon_sha256":"d8f221822405e97cca96938cd6aad96be0bed67c753584d0176317834b2a5dcc"},"schema_version":"1.0","source":{"id":"astro-ph/0109172","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0109172","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0109172v1","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0109172","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"pith_short_12","alias_value":"N2WDYSIU4I6I","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"pith_short_16","alias_value":"N2WDYSIU4I6IFRGQ","created_at":"2026-07-04T14:11:28Z"},{"alias_kind":"pith_short_8","alias_value":"N2WDYSIU","created_at":"2026-07-04T14:11:28Z"}],"graph_snapshots":[{"event_id":"sha256:b1d8e5c9617e9b05803774d19461bf963377ebecbe06519b0da89c7d49f0af15","target":"graph","created_at":"2026-07-04T14:11:28Z","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/0109172/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The question of the X-ray background has been largely settled over the last 10 years using the ROSAT satellite. About 70-80 % of the soft X-ray background was resolved into discrete sources, which are mainly X-ray and optically unobscured AGNs (Quasars, Sy1). Furthermore we found already several obscured AGNs in deep ROSAT surveys, which are predicted by the population synthesis models for the X-ray background, based on the unified AGN schemes. However, deep X-ray surveys using Chandra} and XMM-Newton allow to test the reliability of these models, which seem to be still far from unique. Recent","authors_text":"G. Hasinger, I. Lehmann, M. Schmidt, S.S. Murray","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2001-09-11T11:43:27Z","title":"Exploring the Early Universe with XMM-Newton"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0109172","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:ccb1accea52d63dc77451f07b1b9452be7d4235f11552641d0706ab31d14d1f1","target":"record","created_at":"2026-07-04T14:11:28Z","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":"90c262e218f07e42dcfc6ad0f27c20ce890bb885e0fb6bb21069732510274df2","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2001-09-11T11:43:27Z","title_canon_sha256":"d8f221822405e97cca96938cd6aad96be0bed67c753584d0176317834b2a5dcc"},"schema_version":"1.0","source":{"id":"astro-ph/0109172","kind":"arxiv","version":1}},"canonical_sha256":"6eac3c4914e23c82c4d0866290a7da8869805d91382b0181b737304ea771e53e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"6eac3c4914e23c82c4d0866290a7da8869805d91382b0181b737304ea771e53e","first_computed_at":"2026-07-04T14:11:28.125403Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T14:11:28.125403Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"xAd0XIEQ+4b932EDgY61gRHmfEsE8dEbwOrsA9YXUkrZKtsPzjXb+FQgb3F7W1PHiGXYOZRFQ+HMj00tI+1yBQ==","signature_status":"signed_v1","signed_at":"2026-07-04T14:11:28.125931Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0109172","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ccb1accea52d63dc77451f07b1b9452be7d4235f11552641d0706ab31d14d1f1","sha256:b1d8e5c9617e9b05803774d19461bf963377ebecbe06519b0da89c7d49f0af15"],"state_sha256":"6fd63ddb92f5df199a9aa3acda4e652821a6865e24808b6089df3da6a29e6b38"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"2u1i36TQkKDhH1aBY9XFi9xEsP5KjnP+bHBz3ziB3M0x7aLa5icKSOkcy/opOd4aK9sncQL1JQq53IUyloWFCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-07T13:28:15.237653Z","bundle_sha256":"2de22c62070f4481d686fa66864232b49db0266122552786363b1fa5b2c1438e"}}