{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2002:2JBS7ZAXNVDJDGTRXYJQZVJCY7","short_pith_number":"pith:2JBS7ZAX","canonical_record":{"source":{"id":"astro-ph/0210308","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2002-10-15T18:34:39Z","cross_cats_sorted":[],"title_canon_sha256":"98dfc09f5c1ae4ec7d2a1b3447a9b83fe0a8c7bed431006beb6a49e0d7de8b91","abstract_canon_sha256":"33e6636215061a5b88509dd3607f4db7e881799c04fbdf93a5f42ea436e4503b"},"schema_version":"1.0"},"canonical_sha256":"d2432fe4176d46919a71be130cd522c7c2dfa76c6e554da4174151c6317bdb0c","source":{"kind":"arxiv","id":"astro-ph/0210308","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0210308","created_at":"2026-05-18T01:40:42Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0210308v2","created_at":"2026-05-18T01:40:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0210308","created_at":"2026-05-18T01:40:42Z"},{"alias_kind":"pith_short_12","alias_value":"2JBS7ZAXNVDJ","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_16","alias_value":"2JBS7ZAXNVDJDGTR","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_8","alias_value":"2JBS7ZAX","created_at":"2026-05-18T12:25:50Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2002:2JBS7ZAXNVDJDGTRXYJQZVJCY7","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0210308","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2002-10-15T18:34:39Z","cross_cats_sorted":[],"title_canon_sha256":"98dfc09f5c1ae4ec7d2a1b3447a9b83fe0a8c7bed431006beb6a49e0d7de8b91","abstract_canon_sha256":"33e6636215061a5b88509dd3607f4db7e881799c04fbdf93a5f42ea436e4503b"},"schema_version":"1.0"},"canonical_sha256":"d2432fe4176d46919a71be130cd522c7c2dfa76c6e554da4174151c6317bdb0c","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:40:42.044413Z","signature_b64":"KcXF2UECAOsbaojdM/xdrpxra835dAT2wMBBd/HOSmV8iKf6cRWpU11CBFUzXNuyURrMrboP7KZbE6u18PwUDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d2432fe4176d46919a71be130cd522c7c2dfa76c6e554da4174151c6317bdb0c","last_reissued_at":"2026-05-18T01:40:42.043742Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:40:42.043742Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0210308","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:40:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"mF4LAkL5HycNjaH5q38rNrqvqbHMkUey3rSadeIX5NVE8Y2LmSECaUMuJ2KhMU3eLvBRBggZenKXyEKCLfJZBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T00:04:01.388059Z"},"content_sha256":"d3c921c5846ba484f8ba7ee3b7769207198b0fe6c5e0ea993770fe7620e6f939","schema_version":"1.0","event_id":"sha256:d3c921c5846ba484f8ba7ee3b7769207198b0fe6c5e0ea993770fe7620e6f939"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2002:2JBS7ZAXNVDJDGTRXYJQZVJCY7","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Resolving the Source Populations that Contribute to the X-ray Background: The 2 Ms Chandra Deep Field-North Survey","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A. E. Hornschemeier, C. Vignali (Penn State University), D. M. Alexander, D. P. Schneider, F. E. Bauer, G. P. Garmire, W. N. Brandt","submitted_at":"2002-10-15T18:34:39Z","abstract_excerpt":"With ~2 Ms of Chandra exposure, the Chandra Deep Field-North (CDF-N) survey provides the deepest view of the Universe in the 0.5-8.0 keV band. Five hundred and three (503) X-ray sources are detected down to on-axis 0.5-2.0 keV and 2-8 keV flux limits of ~1.5x10^{-17} erg cm^{-2} s^{-1} and ~1.0x10^{-16} erg cm^{-2} s^{-1}, respectively. These flux limits correspond to L_{0.5-8.0 keV}~3x10^{41} erg s^{-1} at z=1 and L_{0.5-8.0 keV}~2x10^{43} erg s^{-1} at z=6; thus this survey is sensitive enough to detect starburst galaxies out to moderate redshift and Seyfert galaxies out to high redshift. We"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0210308","kind":"arxiv","version":2},"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":"2026-05-18T01:40:42Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Fnww1p9+AguazMnbwUXtEV+lXdgR8nME5RN2m/gyd9iAIzrbgHiGaS6XXIM4CSNbUwCzMlXIrHI9/+auXdYzDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T00:04:01.388710Z"},"content_sha256":"fb6dd88c3427c272ec852ee56de4fa9c84ffd43a3488f015a8ddbecdfa9338ef","schema_version":"1.0","event_id":"sha256:fb6dd88c3427c272ec852ee56de4fa9c84ffd43a3488f015a8ddbecdfa9338ef"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7/bundle.json","state_url":"https://pith.science/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7/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":"2026-05-28T00:04:01Z","links":{"resolver":"https://pith.science/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7","bundle":"https://pith.science/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7/bundle.json","state":"https://pith.science/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7/state.json","well_known_bundle":"https://pith.science/.well-known/pith/2JBS7ZAXNVDJDGTRXYJQZVJCY7/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2002:2JBS7ZAXNVDJDGTRXYJQZVJCY7","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":"33e6636215061a5b88509dd3607f4db7e881799c04fbdf93a5f42ea436e4503b","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2002-10-15T18:34:39Z","title_canon_sha256":"98dfc09f5c1ae4ec7d2a1b3447a9b83fe0a8c7bed431006beb6a49e0d7de8b91"},"schema_version":"1.0","source":{"id":"astro-ph/0210308","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0210308","created_at":"2026-05-18T01:40:42Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0210308v2","created_at":"2026-05-18T01:40:42Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0210308","created_at":"2026-05-18T01:40:42Z"},{"alias_kind":"pith_short_12","alias_value":"2JBS7ZAXNVDJ","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_16","alias_value":"2JBS7ZAXNVDJDGTR","created_at":"2026-05-18T12:25:50Z"},{"alias_kind":"pith_short_8","alias_value":"2JBS7ZAX","created_at":"2026-05-18T12:25:50Z"}],"graph_snapshots":[{"event_id":"sha256:fb6dd88c3427c272ec852ee56de4fa9c84ffd43a3488f015a8ddbecdfa9338ef","target":"graph","created_at":"2026-05-18T01:40:42Z","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":"With ~2 Ms of Chandra exposure, the Chandra Deep Field-North (CDF-N) survey provides the deepest view of the Universe in the 0.5-8.0 keV band. Five hundred and three (503) X-ray sources are detected down to on-axis 0.5-2.0 keV and 2-8 keV flux limits of ~1.5x10^{-17} erg cm^{-2} s^{-1} and ~1.0x10^{-16} erg cm^{-2} s^{-1}, respectively. These flux limits correspond to L_{0.5-8.0 keV}~3x10^{41} erg s^{-1} at z=1 and L_{0.5-8.0 keV}~2x10^{43} erg s^{-1} at z=6; thus this survey is sensitive enough to detect starburst galaxies out to moderate redshift and Seyfert galaxies out to high redshift. We","authors_text":"A. E. Hornschemeier, C. Vignali (Penn State University), D. M. Alexander, D. P. Schneider, F. E. Bauer, G. P. Garmire, W. N. Brandt","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2002-10-15T18:34:39Z","title":"Resolving the Source Populations that Contribute to the X-ray Background: The 2 Ms Chandra Deep Field-North Survey"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0210308","kind":"arxiv","version":2},"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:d3c921c5846ba484f8ba7ee3b7769207198b0fe6c5e0ea993770fe7620e6f939","target":"record","created_at":"2026-05-18T01:40:42Z","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":"33e6636215061a5b88509dd3607f4db7e881799c04fbdf93a5f42ea436e4503b","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2002-10-15T18:34:39Z","title_canon_sha256":"98dfc09f5c1ae4ec7d2a1b3447a9b83fe0a8c7bed431006beb6a49e0d7de8b91"},"schema_version":"1.0","source":{"id":"astro-ph/0210308","kind":"arxiv","version":2}},"canonical_sha256":"d2432fe4176d46919a71be130cd522c7c2dfa76c6e554da4174151c6317bdb0c","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d2432fe4176d46919a71be130cd522c7c2dfa76c6e554da4174151c6317bdb0c","first_computed_at":"2026-05-18T01:40:42.043742Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:40:42.043742Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"KcXF2UECAOsbaojdM/xdrpxra835dAT2wMBBd/HOSmV8iKf6cRWpU11CBFUzXNuyURrMrboP7KZbE6u18PwUDw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:40:42.044413Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0210308","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d3c921c5846ba484f8ba7ee3b7769207198b0fe6c5e0ea993770fe7620e6f939","sha256:fb6dd88c3427c272ec852ee56de4fa9c84ffd43a3488f015a8ddbecdfa9338ef"],"state_sha256":"e8458a14595a467d7bf29b732926e434bbac8b7e8cdb6a849928ecb72c508b98"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"d6Px7swH+ii+K2gou5JE6fZmq/c6FmahZo+mvbZS3t+4ZpbHoPjpf6klsKV7EkE8CsXzy7Hcf7q+tsLBKa5mCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T00:04:01.392298Z","bundle_sha256":"d3c957e845955f36c5e51d8c573fbb7c6d3cc9c20eed624def04638324662154"}}