{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2022:Q77Q3RXFDHIOVHJOI2EXUSCQSQ","short_pith_number":"pith:Q77Q3RXF","canonical_record":{"source":{"id":"2211.03910","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.HE","submitted_at":"2022-11-07T23:37:47Z","cross_cats_sorted":[],"title_canon_sha256":"a7089c0b6162b34546b943596c5cb31d94d870ed913e976e38e2140e18514165","abstract_canon_sha256":"53289b05f249c31b0d85e9096b956d2043bc6a95f14d307a6aa84ff1644b225b"},"schema_version":"1.0"},"canonical_sha256":"87ff0dc6e519d0ea9d2e46897a4850942cd9bf1c943b490d13891f8b28a1eecc","source":{"kind":"arxiv","id":"2211.03910","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2211.03910","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"arxiv_version","alias_value":"2211.03910v1","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2211.03910","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"pith_short_12","alias_value":"Q77Q3RXFDHIO","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"pith_short_16","alias_value":"Q77Q3RXFDHIOVHJO","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"pith_short_8","alias_value":"Q77Q3RXF","created_at":"2026-07-05T05:13:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2022:Q77Q3RXFDHIOVHJOI2EXUSCQSQ","target":"record","payload":{"canonical_record":{"source":{"id":"2211.03910","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.HE","submitted_at":"2022-11-07T23:37:47Z","cross_cats_sorted":[],"title_canon_sha256":"a7089c0b6162b34546b943596c5cb31d94d870ed913e976e38e2140e18514165","abstract_canon_sha256":"53289b05f249c31b0d85e9096b956d2043bc6a95f14d307a6aa84ff1644b225b"},"schema_version":"1.0"},"canonical_sha256":"87ff0dc6e519d0ea9d2e46897a4850942cd9bf1c943b490d13891f8b28a1eecc","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T05:13:59.812082Z","signature_b64":"RA/EH/hKMyh9u/ScCb22zlOJEIsKphzLMSPqd2RGLM6aWIdH4FRk6Q4vzdALt/ORMlA/mrs0HRBvZiYPci5NAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"87ff0dc6e519d0ea9d2e46897a4850942cd9bf1c943b490d13891f8b28a1eecc","last_reissued_at":"2026-07-05T05:13:59.811604Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T05:13:59.811604Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2211.03910","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":"2026-07-05T05:13:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"N/ovsV1WDh268IMvYBvJqxYKdZu9t9K0fww9mLXEQGzffVCB2gZDmFdOb4+723nJKEthaJCRgKYY38Kw1DUCAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-07T00:12:49.185617Z"},"content_sha256":"9a922bb88abbf7e5c96174f811ed03aa89cf4100f6491995af4915d056bb75aa","schema_version":"1.0","event_id":"sha256:9a922bb88abbf7e5c96174f811ed03aa89cf4100f6491995af4915d056bb75aa"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2022:Q77Q3RXFDHIOVHJOI2EXUSCQSQ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The ngEHT's Role in Measuring Supermassive Black Hole Spins","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Aditya Tamar, Angelo Ricarte, Paul Tiede, Priyamvada Natarajan, Razieh Emami","submitted_at":"2022-11-07T23:37:47Z","abstract_excerpt":"While supermassive black hole masses have been cataloged across cosmic time, only a few dozen of them have robust spin measurements. By extending and improving the existing Event Horizon Telescope (EHT) array, the next-generation Event Horizon Telescope (ngEHT) will enable multifrequency, polarimetric movies on event horizon scales, which will place new constraints on the space-time and accretion flow. By combining this information, it is anticipated that the ngEHT may be able to measure tens of supermassive black hole masses and spins. In this white paper, we discuss existing spin measurement"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2211.03910","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/2211.03910/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":"2026-07-05T05:13:59Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Kn8cDl7DjRE8oEw7CKBaCcO4PkUIIwU9ZCbhW8PsNwt7pfL3k/frgpSYh++DKslOa0+o/cvnjaVMwRl3EThpCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-07T00:12:49.186162Z"},"content_sha256":"b45089c9613e75ed69d8183fd64f902dfe7449835d30dd41b5621b74ddc97fed","schema_version":"1.0","event_id":"sha256:b45089c9613e75ed69d8183fd64f902dfe7449835d30dd41b5621b74ddc97fed"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ/bundle.json","state_url":"https://pith.science/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ/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":"2026-08-07T00:12:49Z","links":{"resolver":"https://pith.science/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ","bundle":"https://pith.science/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ/bundle.json","state":"https://pith.science/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/Q77Q3RXFDHIOVHJOI2EXUSCQSQ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2022:Q77Q3RXFDHIOVHJOI2EXUSCQSQ","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":"53289b05f249c31b0d85e9096b956d2043bc6a95f14d307a6aa84ff1644b225b","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.HE","submitted_at":"2022-11-07T23:37:47Z","title_canon_sha256":"a7089c0b6162b34546b943596c5cb31d94d870ed913e976e38e2140e18514165"},"schema_version":"1.0","source":{"id":"2211.03910","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2211.03910","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"arxiv_version","alias_value":"2211.03910v1","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2211.03910","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"pith_short_12","alias_value":"Q77Q3RXFDHIO","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"pith_short_16","alias_value":"Q77Q3RXFDHIOVHJO","created_at":"2026-07-05T05:13:59Z"},{"alias_kind":"pith_short_8","alias_value":"Q77Q3RXF","created_at":"2026-07-05T05:13:59Z"}],"graph_snapshots":[{"event_id":"sha256:b45089c9613e75ed69d8183fd64f902dfe7449835d30dd41b5621b74ddc97fed","target":"graph","created_at":"2026-07-05T05:13:59Z","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/2211.03910/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"While supermassive black hole masses have been cataloged across cosmic time, only a few dozen of them have robust spin measurements. By extending and improving the existing Event Horizon Telescope (EHT) array, the next-generation Event Horizon Telescope (ngEHT) will enable multifrequency, polarimetric movies on event horizon scales, which will place new constraints on the space-time and accretion flow. By combining this information, it is anticipated that the ngEHT may be able to measure tens of supermassive black hole masses and spins. In this white paper, we discuss existing spin measurement","authors_text":"Aditya Tamar, Angelo Ricarte, Paul Tiede, Priyamvada Natarajan, Razieh Emami","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.HE","submitted_at":"2022-11-07T23:37:47Z","title":"The ngEHT's Role in Measuring Supermassive Black Hole Spins"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2211.03910","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":"sha256:9a922bb88abbf7e5c96174f811ed03aa89cf4100f6491995af4915d056bb75aa","target":"record","created_at":"2026-07-05T05:13:59Z","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":"53289b05f249c31b0d85e9096b956d2043bc6a95f14d307a6aa84ff1644b225b","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.HE","submitted_at":"2022-11-07T23:37:47Z","title_canon_sha256":"a7089c0b6162b34546b943596c5cb31d94d870ed913e976e38e2140e18514165"},"schema_version":"1.0","source":{"id":"2211.03910","kind":"arxiv","version":1}},"canonical_sha256":"87ff0dc6e519d0ea9d2e46897a4850942cd9bf1c943b490d13891f8b28a1eecc","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"87ff0dc6e519d0ea9d2e46897a4850942cd9bf1c943b490d13891f8b28a1eecc","first_computed_at":"2026-07-05T05:13:59.811604Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T05:13:59.811604Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"RA/EH/hKMyh9u/ScCb22zlOJEIsKphzLMSPqd2RGLM6aWIdH4FRk6Q4vzdALt/ORMlA/mrs0HRBvZiYPci5NAw==","signature_status":"signed_v1","signed_at":"2026-07-05T05:13:59.812082Z","signed_message":"canonical_sha256_bytes"},"source_id":"2211.03910","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:9a922bb88abbf7e5c96174f811ed03aa89cf4100f6491995af4915d056bb75aa","sha256:b45089c9613e75ed69d8183fd64f902dfe7449835d30dd41b5621b74ddc97fed"],"state_sha256":"cc15445f96152c27a27d5adc9f36398538274c708422c3fb5294cb1c7bb6b100"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"6sBsJdW9OrGck9WNNwn4BFKE0XQYTbCtVPoECs22p2GqWJoyGtUE+3DeGiFuSXNKJ9hXcqzG3+juZu5IgqppCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-07T00:12:49.190051Z","bundle_sha256":"ce359ccc961dc0468b03714fda8d6e290e95e360c197bbabf79080d968af12b4"}}