{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2022:OBSXUHJGOR7JT2E6WPWXPHD7FX","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":"7bca22d870c187f41d307189d8e5dc424a94dbcba9553b8b7f9322d2875f5a42","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2022-05-24T18:00:02Z","title_canon_sha256":"1e13a32f6aaa63c5b76d5dd81e4f8aed85fdece3af039a6c72d35024f0c0f54a"},"schema_version":"1.0","source":{"id":"2205.12281","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2205.12281","created_at":"2026-07-05T04:41:41Z"},{"alias_kind":"arxiv_version","alias_value":"2205.12281v1","created_at":"2026-07-05T04:41:41Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2205.12281","created_at":"2026-07-05T04:41:41Z"},{"alias_kind":"pith_short_12","alias_value":"OBSXUHJGOR7J","created_at":"2026-07-05T04:41:41Z"},{"alias_kind":"pith_short_16","alias_value":"OBSXUHJGOR7JT2E6","created_at":"2026-07-05T04:41:41Z"},{"alias_kind":"pith_short_8","alias_value":"OBSXUHJG","created_at":"2026-07-05T04:41:41Z"}],"graph_snapshots":[{"event_id":"sha256:22011824839002daa7d868ac7e2c0a6dbd337cc2fea58c84fb3ec3fe27ba01b0","target":"graph","created_at":"2026-07-05T04:41:41Z","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/2205.12281/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We study diffuse radio emission in the galaxy cluster A1550, with the aim of constraining particle re-acceleration in the intra-cluster medium. We exploit observations at four different frequencies: 54, 144, 400 and 1400 MHz. To complement our analysis, we make use of archival Chandra X-ray data. At all frequencies we detect an ultra-steep spectrum radio halo ($S_\\nu \\propto \\nu^{-1.6}$) with an extent of 1.2 Mpc at 54 MHz. Its morphology follows the distribution of the thermal intra-cluster medium inferred from the Chandra observation. West of the centrally located head-tail radio galaxy, we ","authors_text":"A. Botteon, C. J. Riseley, C. Nanci, D. Dallacasa. D. N. Hoang, F. De Gasperin, F. Gastaldello, G. Brunetti, G. Di Gennaro, H. W. Edler, K. Rajpurohit, M. Br\\\"uggen, M. Gaspari, M. Rossetti, R. J. van Weeren, T. Pasini, V. Cuciti","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2022-05-24T18:00:02Z","title":"Particle re-acceleration and diffuse radio sources in the galaxy cluster Abell 1550"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2205.12281","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":"sha256:542c585d91b71373d1d9f7394462b3cc93e46a5f12f4423e2b705ad5d1f6d2b3","target":"record","created_at":"2026-07-05T04:41:41Z","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":"7bca22d870c187f41d307189d8e5dc424a94dbcba9553b8b7f9322d2875f5a42","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.CO","submitted_at":"2022-05-24T18:00:02Z","title_canon_sha256":"1e13a32f6aaa63c5b76d5dd81e4f8aed85fdece3af039a6c72d35024f0c0f54a"},"schema_version":"1.0","source":{"id":"2205.12281","kind":"arxiv","version":1}},"canonical_sha256":"70657a1d26747e99e89eb3ed779c7f2dfa2bfe62ad73e1d78c1cf1f757e8af77","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"70657a1d26747e99e89eb3ed779c7f2dfa2bfe62ad73e1d78c1cf1f757e8af77","first_computed_at":"2026-07-05T04:41:41.950422Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T04:41:41.950422Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"8f+B1LLs6vuhZfbWY2WE0MaCDgN3gTWYGCMLacWl3xlTRfmaeDVNaoBxr0KhsWxYnxOFW3BJbAtA64q+3D+qDw==","signature_status":"signed_v1","signed_at":"2026-07-05T04:41:41.950815Z","signed_message":"canonical_sha256_bytes"},"source_id":"2205.12281","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:542c585d91b71373d1d9f7394462b3cc93e46a5f12f4423e2b705ad5d1f6d2b3","sha256:22011824839002daa7d868ac7e2c0a6dbd337cc2fea58c84fb3ec3fe27ba01b0"],"state_sha256":"1b9f291f506460aa6b26b9546a67092dd592661d9820e8865ec06e6f65f9c46c"}