{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2011:KJWGT7E2GXI3C4GXIQDOIFME7W","short_pith_number":"pith:KJWGT7E2","canonical_record":{"source":{"id":"1107.0646","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/3.0/","primary_cat":"astro-ph.CO","submitted_at":"2011-07-04T15:00:24Z","cross_cats_sorted":[],"title_canon_sha256":"4def1a21ad68365d2409f0fbac0f05614bea491e0ec792874d7a0d310d36a82c","abstract_canon_sha256":"1f69ff212d63aa59166dc7c558b1836f1b5148a02015323de083152f376a85a7"},"schema_version":"1.0"},"canonical_sha256":"526c69fc9a35d1b170d74406e41584fdb18916be1182a7a5a3c6f1fe58bc30d9","source":{"kind":"arxiv","id":"1107.0646","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1107.0646","created_at":"2026-05-18T02:01:25Z"},{"alias_kind":"arxiv_version","alias_value":"1107.0646v1","created_at":"2026-05-18T02:01:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1107.0646","created_at":"2026-05-18T02:01:25Z"},{"alias_kind":"pith_short_12","alias_value":"KJWGT7E2GXI3","created_at":"2026-05-18T12:26:32Z"},{"alias_kind":"pith_short_16","alias_value":"KJWGT7E2GXI3C4GX","created_at":"2026-05-18T12:26:32Z"},{"alias_kind":"pith_short_8","alias_value":"KJWGT7E2","created_at":"2026-05-18T12:26:32Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2011:KJWGT7E2GXI3C4GXIQDOIFME7W","target":"record","payload":{"canonical_record":{"source":{"id":"1107.0646","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/3.0/","primary_cat":"astro-ph.CO","submitted_at":"2011-07-04T15:00:24Z","cross_cats_sorted":[],"title_canon_sha256":"4def1a21ad68365d2409f0fbac0f05614bea491e0ec792874d7a0d310d36a82c","abstract_canon_sha256":"1f69ff212d63aa59166dc7c558b1836f1b5148a02015323de083152f376a85a7"},"schema_version":"1.0"},"canonical_sha256":"526c69fc9a35d1b170d74406e41584fdb18916be1182a7a5a3c6f1fe58bc30d9","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:01:25.113916Z","signature_b64":"RyAW5110EbGiYgTh+hP9wgd58XOyHwTDk2hq9Kzq9b4xmCcV5Hyqp84WJb6fjgd0XWkHKs9UpKB1l3nW9jhcCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"526c69fc9a35d1b170d74406e41584fdb18916be1182a7a5a3c6f1fe58bc30d9","last_reissued_at":"2026-05-18T02:01:25.113358Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:01:25.113358Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1107.0646","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":"2026-05-18T02:01:25Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"j/bgA0bQCJUDqa3hTh036uVQHHvjqjlY5G9b4bXhx17uYz+B3kqly4E8dUkiHEokDUXMO1OFuirn+2fnHMa8Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T00:09:18.405820Z"},"content_sha256":"60bf1715e3e4075fa4e994cbb49ddd6238a655580ff8598c5f84228a02c6ba23","schema_version":"1.0","event_id":"sha256:60bf1715e3e4075fa4e994cbb49ddd6238a655580ff8598c5f84228a02c6ba23"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2011:KJWGT7E2GXI3C4GXIQDOIFME7W","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Discovering the missing 2.2<z<3 quasars by combining optical variability and optical/near-IR colors","license":"http://creativecommons.org/licenses/by-nc-sa/3.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"Fuyan Bian, Kasper B. Schmidt, Linhua Jiang, Ran Wang, Xiaohui Fan, Xue-Bing Wu","submitted_at":"2011-07-04T15:00:24Z","abstract_excerpt":"The identifications of quasars in the redshift range 2.2<z<3 are known to be very inefficient as their optical colors are indistinguishable from those of stars. Recent studies have proposed to use optical variability or near-IR colors to improve the identifications of the missing quasars in this redshift range. Here we present a case study by combining both factors. We select a sample of 70 quasar candidates from variables in SDSS Stripe 82, which are non-UV excess sources and have UKIDSS near-IR public data. They are clearly separated into two parts on the Y-K/g-z color-color diagram, and 59 "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1107.0646","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":"2026-05-18T02:01:25Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sueXkPmBsQmBO+A9twfPwkmZnH7HU24xtBL9QILH68pGwmcXjMau54QNBfVxNzT5f04hwZdSj87gWaEHfsMyCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T00:09:18.406213Z"},"content_sha256":"57d1972bd8892fac7b4267b65a3b7af111ace942e8aba14f7a8c81b16e3e6934","schema_version":"1.0","event_id":"sha256:57d1972bd8892fac7b4267b65a3b7af111ace942e8aba14f7a8c81b16e3e6934"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/KJWGT7E2GXI3C4GXIQDOIFME7W/bundle.json","state_url":"https://pith.science/pith/KJWGT7E2GXI3C4GXIQDOIFME7W/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/KJWGT7E2GXI3C4GXIQDOIFME7W/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":"2026-05-30T00:09:18Z","links":{"resolver":"https://pith.science/pith/KJWGT7E2GXI3C4GXIQDOIFME7W","bundle":"https://pith.science/pith/KJWGT7E2GXI3C4GXIQDOIFME7W/bundle.json","state":"https://pith.science/pith/KJWGT7E2GXI3C4GXIQDOIFME7W/state.json","well_known_bundle":"https://pith.science/.well-known/pith/KJWGT7E2GXI3C4GXIQDOIFME7W/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:KJWGT7E2GXI3C4GXIQDOIFME7W","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":"1f69ff212d63aa59166dc7c558b1836f1b5148a02015323de083152f376a85a7","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-sa/3.0/","primary_cat":"astro-ph.CO","submitted_at":"2011-07-04T15:00:24Z","title_canon_sha256":"4def1a21ad68365d2409f0fbac0f05614bea491e0ec792874d7a0d310d36a82c"},"schema_version":"1.0","source":{"id":"1107.0646","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1107.0646","created_at":"2026-05-18T02:01:25Z"},{"alias_kind":"arxiv_version","alias_value":"1107.0646v1","created_at":"2026-05-18T02:01:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1107.0646","created_at":"2026-05-18T02:01:25Z"},{"alias_kind":"pith_short_12","alias_value":"KJWGT7E2GXI3","created_at":"2026-05-18T12:26:32Z"},{"alias_kind":"pith_short_16","alias_value":"KJWGT7E2GXI3C4GX","created_at":"2026-05-18T12:26:32Z"},{"alias_kind":"pith_short_8","alias_value":"KJWGT7E2","created_at":"2026-05-18T12:26:32Z"}],"graph_snapshots":[{"event_id":"sha256:57d1972bd8892fac7b4267b65a3b7af111ace942e8aba14f7a8c81b16e3e6934","target":"graph","created_at":"2026-05-18T02:01:25Z","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":"The identifications of quasars in the redshift range 2.2<z<3 are known to be very inefficient as their optical colors are indistinguishable from those of stars. Recent studies have proposed to use optical variability or near-IR colors to improve the identifications of the missing quasars in this redshift range. Here we present a case study by combining both factors. We select a sample of 70 quasar candidates from variables in SDSS Stripe 82, which are non-UV excess sources and have UKIDSS near-IR public data. They are clearly separated into two parts on the Y-K/g-z color-color diagram, and 59 ","authors_text":"Fuyan Bian, Kasper B. Schmidt, Linhua Jiang, Ran Wang, Xiaohui Fan, Xue-Bing Wu","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by-nc-sa/3.0/","primary_cat":"astro-ph.CO","submitted_at":"2011-07-04T15:00:24Z","title":"Discovering the missing 2.2<z<3 quasars by combining optical variability and optical/near-IR colors"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1107.0646","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":"sha256:60bf1715e3e4075fa4e994cbb49ddd6238a655580ff8598c5f84228a02c6ba23","target":"record","created_at":"2026-05-18T02:01:25Z","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":"1f69ff212d63aa59166dc7c558b1836f1b5148a02015323de083152f376a85a7","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by-nc-sa/3.0/","primary_cat":"astro-ph.CO","submitted_at":"2011-07-04T15:00:24Z","title_canon_sha256":"4def1a21ad68365d2409f0fbac0f05614bea491e0ec792874d7a0d310d36a82c"},"schema_version":"1.0","source":{"id":"1107.0646","kind":"arxiv","version":1}},"canonical_sha256":"526c69fc9a35d1b170d74406e41584fdb18916be1182a7a5a3c6f1fe58bc30d9","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"526c69fc9a35d1b170d74406e41584fdb18916be1182a7a5a3c6f1fe58bc30d9","first_computed_at":"2026-05-18T02:01:25.113358Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:01:25.113358Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"RyAW5110EbGiYgTh+hP9wgd58XOyHwTDk2hq9Kzq9b4xmCcV5Hyqp84WJb6fjgd0XWkHKs9UpKB1l3nW9jhcCQ==","signature_status":"signed_v1","signed_at":"2026-05-18T02:01:25.113916Z","signed_message":"canonical_sha256_bytes"},"source_id":"1107.0646","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:60bf1715e3e4075fa4e994cbb49ddd6238a655580ff8598c5f84228a02c6ba23","sha256:57d1972bd8892fac7b4267b65a3b7af111ace942e8aba14f7a8c81b16e3e6934"],"state_sha256":"b8b25339d50ecfb5b3fe9886fe3d12c0cf661f5b722a6bb064f9ebbade950306"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"mw234wQ4zZKNzzNEOpfuf05d7eYtgEleOpodahUWyQ60Daph8FxiERiXLeVT/nMolU1kgL+VJucs30ZzCJKUAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T00:09:18.409363Z","bundle_sha256":"cdae5ec89472efd55e53b89152d30797a42aa71e4310fbb53ab9647feb3197c0"}}