{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2003:R6SV5MEOA3ADE3LJK2A5CMYP25","short_pith_number":"pith:R6SV5MEO","schema_version":"1.0","canonical_sha256":"8fa55eb08e06c0326d695681d1330fd76281055a79c1f43fa460a5c23b021cd3","source":{"kind":"arxiv","id":"astro-ph/0310298","version":1},"attestation_state":"computed","paper":{"title":"The HELLAS2XMM 1dF survey: on the nature of high X-ray to optical flux ratio sources","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A. Baldi, A. Comastri, C. Vignali, F. Cocchia, F. Fiore, F. La Franca, G.C. Perola, G. Matt, M. Brusa, M. Mignoli, N. Carangelo, P. Ciliegi, P. Severgnini, R. Maiolino, S. Molendi","submitted_at":"2003-10-10T15:25:15Z","abstract_excerpt":"We present results from the photometric and spectroscopic identification of 122 X-ray sources discovered by XMM-Newton in the 2-10 keV band (the HELLAS2XMM 1dF sample). One of the most interesting results (which is found also in deeper sourveys) is that ~20% of the sources have an X-ray to optical flux ratio (X/O) ten times or more higher than that of optically selected AGN. Unlike the faint sources found in the ultra-deep Chandra and XMM-Newton surveys, which reach X-ray (and optical) fluxes >~10 times lower than in the HELLAS2XMM sample, many of the extreme X/O sources in our sample have R~2"},"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":"astro-ph/0310298","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2003-10-10T15:25:15Z","cross_cats_sorted":[],"title_canon_sha256":"da34f4db45014212aa06a0c5b89d1df98c28411f036ca3af8e7b4c3f1e7b2870","abstract_canon_sha256":"2595f431712f051e37ddba1c46f614983a65f3d5264e559bcf10429c8170bbae"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T14:13:04.623124Z","signature_b64":"MRrbQMJ4x3c/gOj243bgoZri9/ooOd8GVk5sHDiiirBtxX/iVdaeY6VksPkhoRARhW/hSj76WCbltKxzXJDKDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"8fa55eb08e06c0326d695681d1330fd76281055a79c1f43fa460a5c23b021cd3","last_reissued_at":"2026-07-04T14:13:04.622720Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T14:13:04.622720Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"The HELLAS2XMM 1dF survey: on the nature of high X-ray to optical flux ratio sources","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A. Baldi, A. Comastri, C. Vignali, F. Cocchia, F. Fiore, F. La Franca, G.C. Perola, G. Matt, M. Brusa, M. Mignoli, N. Carangelo, P. Ciliegi, P. Severgnini, R. Maiolino, S. Molendi","submitted_at":"2003-10-10T15:25:15Z","abstract_excerpt":"We present results from the photometric and spectroscopic identification of 122 X-ray sources discovered by XMM-Newton in the 2-10 keV band (the HELLAS2XMM 1dF sample). One of the most interesting results (which is found also in deeper sourveys) is that ~20% of the sources have an X-ray to optical flux ratio (X/O) ten times or more higher than that of optically selected AGN. Unlike the faint sources found in the ultra-deep Chandra and XMM-Newton surveys, which reach X-ray (and optical) fluxes >~10 times lower than in the HELLAS2XMM sample, many of the extreme X/O sources in our sample have R~2"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0310298","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/0310298/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"},"aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0310298","created_at":"2026-07-04T14:13:04.622773+00:00"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0310298v1","created_at":"2026-07-04T14:13:04.622773+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0310298","created_at":"2026-07-04T14:13:04.622773+00:00"},{"alias_kind":"pith_short_12","alias_value":"R6SV5MEOA3AD","created_at":"2026-07-04T14:13:04.622773+00:00"},{"alias_kind":"pith_short_16","alias_value":"R6SV5MEOA3ADE3LJ","created_at":"2026-07-04T14:13:04.622773+00:00"},{"alias_kind":"pith_short_8","alias_value":"R6SV5MEO","created_at":"2026-07-04T14:13:04.622773+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25","json":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25.json","graph_json":"https://pith.science/api/pith-number/R6SV5MEOA3ADE3LJK2A5CMYP25/graph.json","events_json":"https://pith.science/api/pith-number/R6SV5MEOA3ADE3LJK2A5CMYP25/events.json","paper":"https://pith.science/paper/R6SV5MEO"},"agent_actions":{"view_html":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25","download_json":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25.json","view_paper":"https://pith.science/paper/R6SV5MEO","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=astro-ph/0310298&json=true","fetch_graph":"https://pith.science/api/pith-number/R6SV5MEOA3ADE3LJK2A5CMYP25/graph.json","fetch_events":"https://pith.science/api/pith-number/R6SV5MEOA3ADE3LJK2A5CMYP25/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25/action/timestamp_anchor","attest_storage":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25/action/storage_attestation","attest_author":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25/action/author_attestation","sign_citation":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25/action/citation_signature","submit_replication":"https://pith.science/pith/R6SV5MEOA3ADE3LJK2A5CMYP25/action/replication_record"}},"created_at":"2026-07-04T14:13:04.622773+00:00","updated_at":"2026-07-04T14:13:04.622773+00:00"}