{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:B2FJBCK4NCXHGRVZ3RLUEBZ5K6","short_pith_number":"pith:B2FJBCK4","canonical_record":{"source":{"id":"2102.08470","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-02-16T22:11:25Z","cross_cats_sorted":[],"title_canon_sha256":"f6ce5150f8d06a74f709d6ec274111577538d409cab9b536dbd1f4cfed3636f6","abstract_canon_sha256":"a16f7c5418249d9784e5a45d397991277b244fd3640ec206dcd57e8d0bdb1534"},"schema_version":"1.0"},"canonical_sha256":"0e8a90895c68ae7346b9dc5742073d578fe1f5814e2341c73b639277c4d9ce2a","source":{"kind":"arxiv","id":"2102.08470","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2102.08470","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"arxiv_version","alias_value":"2102.08470v2","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2102.08470","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"pith_short_12","alias_value":"B2FJBCK4NCXH","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"pith_short_16","alias_value":"B2FJBCK4NCXHGRVZ","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"pith_short_8","alias_value":"B2FJBCK4","created_at":"2026-07-05T02:53:00Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:B2FJBCK4NCXHGRVZ3RLUEBZ5K6","target":"record","payload":{"canonical_record":{"source":{"id":"2102.08470","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-02-16T22:11:25Z","cross_cats_sorted":[],"title_canon_sha256":"f6ce5150f8d06a74f709d6ec274111577538d409cab9b536dbd1f4cfed3636f6","abstract_canon_sha256":"a16f7c5418249d9784e5a45d397991277b244fd3640ec206dcd57e8d0bdb1534"},"schema_version":"1.0"},"canonical_sha256":"0e8a90895c68ae7346b9dc5742073d578fe1f5814e2341c73b639277c4d9ce2a","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:53:00.286888Z","signature_b64":"j+eNsxj2WAjKoUwzDGBHlTyk9a1mLUOvVHi0jgadXg/6t0S5r9MBvudl2bVL3K470JzKs65rpMNZ8i7W3kv/CQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0e8a90895c68ae7346b9dc5742073d578fe1f5814e2341c73b639277c4d9ce2a","last_reissued_at":"2026-07-05T02:53:00.286536Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:53:00.286536Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2102.08470","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":"2026-07-05T02:53:00Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Gd2t9GT2awNt7X3F++oIBfGkUXjxLmSMn0m0OBJRKarZeiszozG8NLYklHmvqms7wXINAau1mktMechNuJX7Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T12:45:22.681856Z"},"content_sha256":"9fc8be8736e7a5b908efa6cd8b41a76d1697b2bd3203d1a6ede961e4ea3f4afa","schema_version":"1.0","event_id":"sha256:9fc8be8736e7a5b908efa6cd8b41a76d1697b2bd3203d1a6ede961e4ea3f4afa"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:B2FJBCK4NCXHGRVZ3RLUEBZ5K6","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"What Makes Quadruply Lensed Quasars Quadruple?","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"2), (2) MIT Kavli Institute for Astrophysics, Kaylee M. de Soto (1) ((1) MIT Department of Physics, Paul L. Schechter (1, Richard Luhtaru (1), Space Research)","submitted_at":"2021-02-16T22:11:25Z","abstract_excerpt":"Among known strongly lensed quasar systems, ~25% have gravitational potentials sufficiently flat (and sources sufficiently well aligned) to produce four images rather than two. The projected flattening of the lensing galaxy and tides from neighboring galaxies both contribute to the potential's quadrupole. Witt's hyperbola and Wynne's ellipse permit determination of the overall quadrupole from the positions of the quasar images. The position of the lensing galaxy resolves the distinct contributions of intrinsic ellipticity and tidal shear to that quadrupole. Among 31 quadruply lensed quasars sy"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2102.08470","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2102.08470/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":"2026-07-05T02:53:00Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"soEw1DDyAjdlBQlr9FXJou8Mmz8wqZZEYyTnRbmKbrTYPN3nYkzRP4MYgFYNjjMc31YeFoCWXS9wvZtq0Vb5Bw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-07T12:45:22.682228Z"},"content_sha256":"dfd20efc9c79ba26e29d7e83e8fcd6ce4d7fcc1b51bc56c1611b2c0dbc764263","schema_version":"1.0","event_id":"sha256:dfd20efc9c79ba26e29d7e83e8fcd6ce4d7fcc1b51bc56c1611b2c0dbc764263"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6/bundle.json","state_url":"https://pith.science/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6/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":"2026-07-07T12:45:22Z","links":{"resolver":"https://pith.science/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6","bundle":"https://pith.science/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6/bundle.json","state":"https://pith.science/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6/state.json","well_known_bundle":"https://pith.science/.well-known/pith/B2FJBCK4NCXHGRVZ3RLUEBZ5K6/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:B2FJBCK4NCXHGRVZ3RLUEBZ5K6","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":"a16f7c5418249d9784e5a45d397991277b244fd3640ec206dcd57e8d0bdb1534","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-02-16T22:11:25Z","title_canon_sha256":"f6ce5150f8d06a74f709d6ec274111577538d409cab9b536dbd1f4cfed3636f6"},"schema_version":"1.0","source":{"id":"2102.08470","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2102.08470","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"arxiv_version","alias_value":"2102.08470v2","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2102.08470","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"pith_short_12","alias_value":"B2FJBCK4NCXH","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"pith_short_16","alias_value":"B2FJBCK4NCXHGRVZ","created_at":"2026-07-05T02:53:00Z"},{"alias_kind":"pith_short_8","alias_value":"B2FJBCK4","created_at":"2026-07-05T02:53:00Z"}],"graph_snapshots":[{"event_id":"sha256:dfd20efc9c79ba26e29d7e83e8fcd6ce4d7fcc1b51bc56c1611b2c0dbc764263","target":"graph","created_at":"2026-07-05T02:53:00Z","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/2102.08470/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Among known strongly lensed quasar systems, ~25% have gravitational potentials sufficiently flat (and sources sufficiently well aligned) to produce four images rather than two. The projected flattening of the lensing galaxy and tides from neighboring galaxies both contribute to the potential's quadrupole. Witt's hyperbola and Wynne's ellipse permit determination of the overall quadrupole from the positions of the quasar images. The position of the lensing galaxy resolves the distinct contributions of intrinsic ellipticity and tidal shear to that quadrupole. Among 31 quadruply lensed quasars sy","authors_text":"2), (2) MIT Kavli Institute for Astrophysics, Kaylee M. de Soto (1) ((1) MIT Department of Physics, Paul L. Schechter (1, Richard Luhtaru (1), Space Research)","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-02-16T22:11:25Z","title":"What Makes Quadruply Lensed Quasars Quadruple?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2102.08470","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":"sha256:9fc8be8736e7a5b908efa6cd8b41a76d1697b2bd3203d1a6ede961e4ea3f4afa","target":"record","created_at":"2026-07-05T02:53:00Z","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":"a16f7c5418249d9784e5a45d397991277b244fd3640ec206dcd57e8d0bdb1534","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-02-16T22:11:25Z","title_canon_sha256":"f6ce5150f8d06a74f709d6ec274111577538d409cab9b536dbd1f4cfed3636f6"},"schema_version":"1.0","source":{"id":"2102.08470","kind":"arxiv","version":2}},"canonical_sha256":"0e8a90895c68ae7346b9dc5742073d578fe1f5814e2341c73b639277c4d9ce2a","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0e8a90895c68ae7346b9dc5742073d578fe1f5814e2341c73b639277c4d9ce2a","first_computed_at":"2026-07-05T02:53:00.286536Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T02:53:00.286536Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"j+eNsxj2WAjKoUwzDGBHlTyk9a1mLUOvVHi0jgadXg/6t0S5r9MBvudl2bVL3K470JzKs65rpMNZ8i7W3kv/CQ==","signature_status":"signed_v1","signed_at":"2026-07-05T02:53:00.286888Z","signed_message":"canonical_sha256_bytes"},"source_id":"2102.08470","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9fc8be8736e7a5b908efa6cd8b41a76d1697b2bd3203d1a6ede961e4ea3f4afa","sha256:dfd20efc9c79ba26e29d7e83e8fcd6ce4d7fcc1b51bc56c1611b2c0dbc764263"],"state_sha256":"fa2f9a25278fef7416341fa54a3739ee982ba82261b19a7e59607d55b2dd1759"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VMuII1e5YR8ZnVFqwS+Mj4Rkzs/3pix8+fny4lCVhmS6Ux5yzjrt2ZMl+Njdb4srRuuLiq3U2Hb+bt8vhGnpAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-07T12:45:22.684208Z","bundle_sha256":"f316b64aaf09a992a10651347c3e74f63678d0cd54498262d4204241b1ac8fa8"}}