{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:VXA76HHVO5QEG5RCZ5FJWG53X6","short_pith_number":"pith:VXA76HHV","canonical_record":{"source":{"id":"2502.08713","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-02-12T19:00:02Z","cross_cats_sorted":[],"title_canon_sha256":"fc2cc46f0c501b0b191bb539a55ccf236f21d713d235b16350b5952a760cece5","abstract_canon_sha256":"f7ffefe752d42ea25405558ecb76d852df33a7c687919e2355740e6ba367d55b"},"schema_version":"1.0"},"canonical_sha256":"adc1ff1cf57760437622cf4a9b1bbbbf83c395bfd5afddd3ee7362a46be82700","source":{"kind":"arxiv","id":"2502.08713","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2502.08713","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"arxiv_version","alias_value":"2502.08713v1","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2502.08713","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"pith_short_12","alias_value":"VXA76HHVO5QE","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"pith_short_16","alias_value":"VXA76HHVO5QEG5RC","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"pith_short_8","alias_value":"VXA76HHV","created_at":"2026-07-05T10:13:28Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:VXA76HHVO5QEG5RCZ5FJWG53X6","target":"record","payload":{"canonical_record":{"source":{"id":"2502.08713","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-02-12T19:00:02Z","cross_cats_sorted":[],"title_canon_sha256":"fc2cc46f0c501b0b191bb539a55ccf236f21d713d235b16350b5952a760cece5","abstract_canon_sha256":"f7ffefe752d42ea25405558ecb76d852df33a7c687919e2355740e6ba367d55b"},"schema_version":"1.0"},"canonical_sha256":"adc1ff1cf57760437622cf4a9b1bbbbf83c395bfd5afddd3ee7362a46be82700","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T10:13:28.866226Z","signature_b64":"DN3Q5sldUyRbJaueicjFnI4ubC4YqG4WUQGK1nregKXm0fW71e4wdYq6cNnly4Wz2oHr6C2TDCu+XGdJdIbQDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"adc1ff1cf57760437622cf4a9b1bbbbf83c395bfd5afddd3ee7362a46be82700","last_reissued_at":"2026-07-05T10:13:28.865739Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T10:13:28.865739Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2502.08713","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":"2026-07-05T10:13:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Xkcq2Xq7o4oLYSuPgmFxxgsGzF5wiVq9RtoW3WTrN6z9rc10F9Gp+uTmQfpXFhhQrsKveW01f1qrxIjOm4lJCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-06T11:50:57.704513Z"},"content_sha256":"1cb68edfceeb55860d1348355e51b290042b2389437979a16d3f81c335856f0e","schema_version":"1.0","event_id":"sha256:1cb68edfceeb55860d1348355e51b290042b2389437979a16d3f81c335856f0e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:VXA76HHVO5QEG5RCZ5FJWG53X6","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The low-frequency flattening of the radio spectrum of giant HII regions in M 101","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"A. Basu, B. Adebahr, C. Horellou, D.J. Bomans, D. Vohl, F. De Gasperin, H. D\\'enes, H. W. Edler, L. Gajovi\\'c, M. Br\\\"uggen, M. We\\.zgowiec, T. Pasini, V. Heesen","submitted_at":"2025-02-12T19:00:02Z","abstract_excerpt":"In galaxies, the flattening of the spectrum at low radio frequencies below 300 MHz has been the subject of some debate. A turnover at low frequencies could be caused by multiple physical processes, which can yield new insights into the properties of the ionised gas in the interstellar medium. We investigate the existence and nature of the low-frequency turnover in the HII regions of M 101. We study the nearby galaxy M 101 using the LOw Frequency ARray (LOFAR) at frequencies of 54 and 144 MHz, Apertif at 1370 MHz, and published combined map from the Very Large Array (VLA) and Effelesberg telesc"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2502.08713","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/2502.08713/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":"2026-07-05T10:13:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"T9swSxNDLXpTyjpWcALhUqYtthPE7N8Kf1tOlImjyNPdeiZmzwCERjgVKhm/ODHbBgfRUHD3kiHZCGpJqVBLAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-06T11:50:57.704912Z"},"content_sha256":"04008e0791ec0033e28ae4fbad2d797719e9882b79fecd3a85f5b512a858628d","schema_version":"1.0","event_id":"sha256:04008e0791ec0033e28ae4fbad2d797719e9882b79fecd3a85f5b512a858628d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/VXA76HHVO5QEG5RCZ5FJWG53X6/bundle.json","state_url":"https://pith.science/pith/VXA76HHVO5QEG5RCZ5FJWG53X6/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/VXA76HHVO5QEG5RCZ5FJWG53X6/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":"2026-08-06T11:50:57Z","links":{"resolver":"https://pith.science/pith/VXA76HHVO5QEG5RCZ5FJWG53X6","bundle":"https://pith.science/pith/VXA76HHVO5QEG5RCZ5FJWG53X6/bundle.json","state":"https://pith.science/pith/VXA76HHVO5QEG5RCZ5FJWG53X6/state.json","well_known_bundle":"https://pith.science/.well-known/pith/VXA76HHVO5QEG5RCZ5FJWG53X6/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:VXA76HHVO5QEG5RCZ5FJWG53X6","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":"f7ffefe752d42ea25405558ecb76d852df33a7c687919e2355740e6ba367d55b","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-02-12T19:00:02Z","title_canon_sha256":"fc2cc46f0c501b0b191bb539a55ccf236f21d713d235b16350b5952a760cece5"},"schema_version":"1.0","source":{"id":"2502.08713","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2502.08713","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"arxiv_version","alias_value":"2502.08713v1","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2502.08713","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"pith_short_12","alias_value":"VXA76HHVO5QE","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"pith_short_16","alias_value":"VXA76HHVO5QEG5RC","created_at":"2026-07-05T10:13:28Z"},{"alias_kind":"pith_short_8","alias_value":"VXA76HHV","created_at":"2026-07-05T10:13:28Z"}],"graph_snapshots":[{"event_id":"sha256:04008e0791ec0033e28ae4fbad2d797719e9882b79fecd3a85f5b512a858628d","target":"graph","created_at":"2026-07-05T10:13:28Z","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/2502.08713/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In galaxies, the flattening of the spectrum at low radio frequencies below 300 MHz has been the subject of some debate. A turnover at low frequencies could be caused by multiple physical processes, which can yield new insights into the properties of the ionised gas in the interstellar medium. We investigate the existence and nature of the low-frequency turnover in the HII regions of M 101. We study the nearby galaxy M 101 using the LOw Frequency ARray (LOFAR) at frequencies of 54 and 144 MHz, Apertif at 1370 MHz, and published combined map from the Very Large Array (VLA) and Effelesberg telesc","authors_text":"A. Basu, B. Adebahr, C. Horellou, D.J. Bomans, D. Vohl, F. De Gasperin, H. D\\'enes, H. W. Edler, L. Gajovi\\'c, M. Br\\\"uggen, M. We\\.zgowiec, T. Pasini, V. Heesen","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-02-12T19:00:02Z","title":"The low-frequency flattening of the radio spectrum of giant HII regions in M 101"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2502.08713","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":"sha256:1cb68edfceeb55860d1348355e51b290042b2389437979a16d3f81c335856f0e","target":"record","created_at":"2026-07-05T10:13:28Z","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":"f7ffefe752d42ea25405558ecb76d852df33a7c687919e2355740e6ba367d55b","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2025-02-12T19:00:02Z","title_canon_sha256":"fc2cc46f0c501b0b191bb539a55ccf236f21d713d235b16350b5952a760cece5"},"schema_version":"1.0","source":{"id":"2502.08713","kind":"arxiv","version":1}},"canonical_sha256":"adc1ff1cf57760437622cf4a9b1bbbbf83c395bfd5afddd3ee7362a46be82700","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"adc1ff1cf57760437622cf4a9b1bbbbf83c395bfd5afddd3ee7362a46be82700","first_computed_at":"2026-07-05T10:13:28.865739Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T10:13:28.865739Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"DN3Q5sldUyRbJaueicjFnI4ubC4YqG4WUQGK1nregKXm0fW71e4wdYq6cNnly4Wz2oHr6C2TDCu+XGdJdIbQDQ==","signature_status":"signed_v1","signed_at":"2026-07-05T10:13:28.866226Z","signed_message":"canonical_sha256_bytes"},"source_id":"2502.08713","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1cb68edfceeb55860d1348355e51b290042b2389437979a16d3f81c335856f0e","sha256:04008e0791ec0033e28ae4fbad2d797719e9882b79fecd3a85f5b512a858628d"],"state_sha256":"d02b4cd0b046df6f3d733d055742aa0e78050b4a2604c05ca1debbbec9a1f408"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"acGAiTTfg6nzEKEXWWIVVcziOglB/55eNT2Y+yk5DkFovOn9EOKLwzaMtIuTcLv5BKPQmnhuD1bi9e86FARaBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-06T11:50:57.708952Z","bundle_sha256":"94afc47e9f6a9e821dee201eb2dfbcc20432b67b35ce1e23b34a8387645e6340"}}