{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2021:Q3Z4OAYR7UE6T4ZQJYJU5EVG22","short_pith_number":"pith:Q3Z4OAYR","schema_version":"1.0","canonical_sha256":"86f3c70311fd09e9f3304e134e92a6d690e1e1053ad027bdefeede422b974684","source":{"kind":"arxiv","id":"2105.01169","version":1},"attestation_state":"computed","paper":{"title":"First M87 Event Horizon Telescope Results. VII. Polarization of the Ring","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.HE","authors_text":"The Event Horizon Telescope Collaboration","submitted_at":"2021-05-03T21:12:04Z","abstract_excerpt":"In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology. This structure originates from synchrotron emission produced by relativistic plasma located in the immediate vicinity of the black hole. Here we present the corresponding linear-polarimetric EHT images of the center of M87. We find that only a part of the ring is significantly polarized. The resolved fractional linear polarization has a maximum located i"},"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":"2105.01169","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.HE","submitted_at":"2021-05-03T21:12:04Z","cross_cats_sorted":["astro-ph.GA"],"title_canon_sha256":"de876f357e3b617131f22ea86f301d922fa3225d52cd518509959fa42ca60016","abstract_canon_sha256":"af12adb92feecc1b2ff6985094883668d6f2bb01fe1c2d33bcdcdfc89723fec4"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T02:37:14.065629Z","signature_b64":"vu5TtxkBIKRTbASI61oDzkM0XZFGuF3M8Ye4xq8PIbswaPO8yyIDfHMFEZ0+6hr/5ixHsaBewYBD33KUiiaoDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"86f3c70311fd09e9f3304e134e92a6d690e1e1053ad027bdefeede422b974684","last_reissued_at":"2026-07-05T02:37:14.065116Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T02:37:14.065116Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"First M87 Event Horizon Telescope Results. VII. Polarization of the Ring","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.GA"],"primary_cat":"astro-ph.HE","authors_text":"The Event Horizon Telescope Collaboration","submitted_at":"2021-05-03T21:12:04Z","abstract_excerpt":"In 2017 April, the Event Horizon Telescope (EHT) observed the near-horizon region around the supermassive black hole at the core of the M87 galaxy. These 1.3 mm wavelength observations revealed a compact asymmetric ring-like source morphology. This structure originates from synchrotron emission produced by relativistic plasma located in the immediate vicinity of the black hole. Here we present the corresponding linear-polarimetric EHT images of the center of M87. We find that only a part of the ring is significantly polarized. The resolved fractional linear polarization has a maximum located i"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2105.01169","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/2105.01169/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":"2105.01169","created_at":"2026-07-05T02:37:14.065184+00:00"},{"alias_kind":"arxiv_version","alias_value":"2105.01169v1","created_at":"2026-07-05T02:37:14.065184+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2105.01169","created_at":"2026-07-05T02:37:14.065184+00:00"},{"alias_kind":"pith_short_12","alias_value":"Q3Z4OAYR7UE6","created_at":"2026-07-05T02:37:14.065184+00:00"},{"alias_kind":"pith_short_16","alias_value":"Q3Z4OAYR7UE6T4ZQ","created_at":"2026-07-05T02:37:14.065184+00:00"},{"alias_kind":"pith_short_8","alias_value":"Q3Z4OAYR","created_at":"2026-07-05T02:37:14.065184+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":9,"internal_anchor_count":1,"sample":[{"citing_arxiv_id":"2607.05909","citing_title":"Probing near-zone magnetic fields with extreme mass-ratio inspirals","ref_index":53,"is_internal_anchor":true},{"citing_arxiv_id":"2606.26166","citing_title":"Images of Braneworld black holes with radiatively inefficient accretion flows","ref_index":48,"is_internal_anchor":false},{"citing_arxiv_id":"2606.20284","citing_title":"Constitutive birefringence and critical curves in the rotating Garc\\'ia--D\\'iaz black hole","ref_index":58,"is_internal_anchor":false},{"citing_arxiv_id":"2606.00166","citing_title":"Parametric resonance amplification of gravitational waves in dynamical Chern-Simons gravity","ref_index":45,"is_internal_anchor":false},{"citing_arxiv_id":"2605.25625","citing_title":"Periodic orbits and gravitational waveforms around a Schwarzschild black hole with a cloud of strings embedded in perfect fluid dark matter","ref_index":14,"is_internal_anchor":false},{"citing_arxiv_id":"2605.26395","citing_title":"Equatorial Circular Motion of Charged Test Particles in a Weakly Magnetized Taub--NUT Background","ref_index":9,"is_internal_anchor":false},{"citing_arxiv_id":"2604.22309","citing_title":"Photon Propagation and Black Hole Imaging in Kruglov Nonlinear Electrodynamics","ref_index":20,"is_internal_anchor":false},{"citing_arxiv_id":"2604.22309","citing_title":"Photon Propagation and Black Hole Imaging in Kruglov Nonlinear Electrodynamics","ref_index":20,"is_internal_anchor":false},{"citing_arxiv_id":"2604.16551","citing_title":"Photon rings and shadows of black holes with non-minimal couplings between curvature and electromagnetic field","ref_index":16,"is_internal_anchor":false}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22","json":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22.json","graph_json":"https://pith.science/api/pith-number/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/graph.json","events_json":"https://pith.science/api/pith-number/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/events.json","paper":"https://pith.science/paper/Q3Z4OAYR"},"agent_actions":{"view_html":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22","download_json":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22.json","view_paper":"https://pith.science/paper/Q3Z4OAYR","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2105.01169&json=true","fetch_graph":"https://pith.science/api/pith-number/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/graph.json","fetch_events":"https://pith.science/api/pith-number/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/action/timestamp_anchor","attest_storage":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/action/storage_attestation","attest_author":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/action/author_attestation","sign_citation":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/action/citation_signature","submit_replication":"https://pith.science/pith/Q3Z4OAYR7UE6T4ZQJYJU5EVG22/action/replication_record"}},"created_at":"2026-07-05T02:37:14.065184+00:00","updated_at":"2026-07-05T02:37:14.065184+00:00"}