{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2026:44Z4JOLUQSM3N2NGCNB6REHLMT","short_pith_number":"pith:44Z4JOLU","schema_version":"1.0","canonical_sha256":"e733c4b9748499b6e9a61343e890eb64ded29b897e797b20c5f7768455337ff9","source":{"kind":"arxiv","id":"2604.19867","version":1},"attestation_state":"computed","paper":{"title":"Hamilton's Object Revisited: A challenging source redshift of a strong lensing configuration","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"Re-analysis of spectra confirms Hamilton's object has redshift 0.82 rather than 3.2","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"Emilio E. Falco, Jenny Wagner, Richard E. Griffiths","submitted_at":"2026-04-21T18:00:01Z","abstract_excerpt":"Low-resolution spectrographs used to have difficulties to determine redshifts of galaxies at $z\\approx1$ and $z\\approx3$. Spectral emission and absorption lines of magnesium and iron redshifted to $z\\approx1$ fall close to hydrogen, silicon, and oxygen lines at $z\\approx3$. Here, we demonstrate that, even with modern, integrated field unit spectrographs, this task remains challenging. Hamilton's object, a blue star-forming galaxy, gravitationally lensed into three multiple images by the galaxy cluster SDSS J223010.47-081017.8 is such a case. Using the Blue Keck Cosmic Web Imager, its redshift "},"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":true,"formal_links_present":false},"canonical_record":{"source":{"id":"2604.19867","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2026-04-21T18:00:01Z","cross_cats_sorted":["astro-ph.CO"],"title_canon_sha256":"f35b90bcf1af4401b67e4e5cbf51ff4887fe0dcd4cbf0cc41c296ca1013fd63d","abstract_canon_sha256":"6192877fc4f3d605c03c57293aa4ae7b49039b3aab0c92e3b173284e7a76a05f"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-10T14:10:50.519041Z","signature_b64":"QptIiYDe0iLOduk5p/4YwjqI6Ijx5flWISYWv7u3DserKFbpIzvxTcZ5Lgr6lmvGHVnmFLse8iAdPTOfhv4fBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e733c4b9748499b6e9a61343e890eb64ded29b897e797b20c5f7768455337ff9","last_reissued_at":"2026-06-10T14:10:50.518145Z","signature_status":"signed_v1","first_computed_at":"2026-06-10T14:10:50.518145Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Hamilton's Object Revisited: A challenging source redshift of a strong lensing configuration","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"Re-analysis of spectra confirms Hamilton's object has redshift 0.82 rather than 3.2","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"Emilio E. Falco, Jenny Wagner, Richard E. Griffiths","submitted_at":"2026-04-21T18:00:01Z","abstract_excerpt":"Low-resolution spectrographs used to have difficulties to determine redshifts of galaxies at $z\\approx1$ and $z\\approx3$. Spectral emission and absorption lines of magnesium and iron redshifted to $z\\approx1$ fall close to hydrogen, silicon, and oxygen lines at $z\\approx3$. Here, we demonstrate that, even with modern, integrated field unit spectrographs, this task remains challenging. Hamilton's object, a blue star-forming galaxy, gravitationally lensed into three multiple images by the galaxy cluster SDSS J223010.47-081017.8 is such a case. Using the Blue Keck Cosmic Web Imager, its redshift "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"The re-evaluation confirms the previous result based on 6 absorption features, z=0.820 ± 0.001 and 4 emission features, z=0.821 ± 0.002. The alternative z=3.199± 0.003, based on 6 absorption and 2 emission lines is a worse fit, also compared to other spectra.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the chosen line identifications at z=0.82 are the correct physical assignment and that the PypeIt pipeline plus custom Python fitting routines introduce no systematic wavelength or flux errors that would alter the relative goodness-of-fit between the two redshift solutions.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Re-analysis of KCWI spectra with PypeIt confirms Hamilton's object redshift at z=0.820, showing the MOIRCS z=3.2 fit is worse and the earlier data inconclusive due to slit coverage and calibration issues.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Re-analysis of spectra confirms Hamilton's object has redshift 0.82 rather than 3.2","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"81b625203c703c1590f4e465e6cf4f0e18be29efdf8b32eb1ce45736491bc81f"},"source":{"id":"2604.19867","kind":"arxiv","version":1},"verdict":{"id":"db0aa6d4-8692-4ac2-8382-aba62d3b98c0","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T01:50:37.275662Z","strongest_claim":"The re-evaluation confirms the previous result based on 6 absorption features, z=0.820 ± 0.001 and 4 emission features, z=0.821 ± 0.002. The alternative z=3.199± 0.003, based on 6 absorption and 2 emission lines is a worse fit, also compared to other spectra.","one_line_summary":"Re-analysis of KCWI spectra with PypeIt confirms Hamilton's object redshift at z=0.820, showing the MOIRCS z=3.2 fit is worse and the earlier data inconclusive due to slit coverage and calibration issues.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the chosen line identifications at z=0.82 are the correct physical assignment and that the PypeIt pipeline plus custom Python fitting routines introduce no systematic wavelength or flux errors that would alter the relative goodness-of-fit between the two redshift solutions.","pith_extraction_headline":"Re-analysis of spectra confirms Hamilton's object has redshift 0.82 rather than 3.2"},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.19867/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-21T15:42:29.235025Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-20T02:34:27.545494Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"077049a3e2fd589e13568ee03887f91c19161cb4cb3e1a3758a5405c75528de9"},"references":{"count":40,"sample":[{"doi":"","year":2011,"title":"Bayliss, M. B., Hennawi, J. F., Gladders, M. D., et al. 2011, ApJS, 193, 8","work_id":"1b72dd4d-468b-4e40-8d40-3c7f5c17c8cf","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2017,"title":"B., Grillo, C., Rosati, P., et al","work_id":"d3c62ee2-211d-4040-87e8-6f309ceaa4b0","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2025,"title":"2025, MNRAS, 537, 2662","work_id":"6ec82412-da27-4eee-b5cc-056b78e143d9","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2018,"title":"2018, A&A, 617, A62","work_id":"4c8f6400-09be-4175-9b6b-4fd12c8c912c","ref_index":4,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2021,"title":"E., Rudisel, M., Wagner, J., et al","work_id":"920577b7-78e0-4641-b0d1-0415119dd686","ref_index":5,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":40,"snapshot_sha256":"12f17d4baa600d4ddc59fba236daef873510b82878af30704afb63efbfa55e76","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":"2604.19867","created_at":"2026-06-10T14:10:50.518293+00:00"},{"alias_kind":"arxiv_version","alias_value":"2604.19867v1","created_at":"2026-06-10T14:10:50.518293+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2604.19867","created_at":"2026-06-10T14:10:50.518293+00:00"},{"alias_kind":"pith_short_12","alias_value":"44Z4JOLUQSM3","created_at":"2026-06-10T14:10:50.518293+00:00"},{"alias_kind":"pith_short_16","alias_value":"44Z4JOLUQSM3N2NG","created_at":"2026-06-10T14:10:50.518293+00:00"},{"alias_kind":"pith_short_8","alias_value":"44Z4JOLU","created_at":"2026-06-10T14:10:50.518293+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT","json":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT.json","graph_json":"https://pith.science/api/pith-number/44Z4JOLUQSM3N2NGCNB6REHLMT/graph.json","events_json":"https://pith.science/api/pith-number/44Z4JOLUQSM3N2NGCNB6REHLMT/events.json","paper":"https://pith.science/paper/44Z4JOLU"},"agent_actions":{"view_html":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT","download_json":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT.json","view_paper":"https://pith.science/paper/44Z4JOLU","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2604.19867&json=true","fetch_graph":"https://pith.science/api/pith-number/44Z4JOLUQSM3N2NGCNB6REHLMT/graph.json","fetch_events":"https://pith.science/api/pith-number/44Z4JOLUQSM3N2NGCNB6REHLMT/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT/action/timestamp_anchor","attest_storage":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT/action/storage_attestation","attest_author":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT/action/author_attestation","sign_citation":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT/action/citation_signature","submit_replication":"https://pith.science/pith/44Z4JOLUQSM3N2NGCNB6REHLMT/action/replication_record"}},"created_at":"2026-06-10T14:10:50.518293+00:00","updated_at":"2026-06-10T14:10:50.518293+00:00"}