{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:5XUJUFPAH2XHST6QQB7ZIW4ZQI","short_pith_number":"pith:5XUJUFPA","canonical_record":{"source":{"id":"1310.2870","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2013-10-10T16:17:59Z","cross_cats_sorted":[],"title_canon_sha256":"a11f8d9a558c499eada964f58a1a7dee068225cf21d07130f67048bb73ad2445","abstract_canon_sha256":"4bef72286e7937f646df4d47c4830fa976d94b460accac7640c9307a1f1051f0"},"schema_version":"1.0"},"canonical_sha256":"ede89a15e03eae794fd0807f945b998216ccd5cffaf2389e7f329f27116cc2aa","source":{"kind":"arxiv","id":"1310.2870","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1310.2870","created_at":"2026-05-18T01:47:06Z"},{"alias_kind":"arxiv_version","alias_value":"1310.2870v1","created_at":"2026-05-18T01:47:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1310.2870","created_at":"2026-05-18T01:47:06Z"},{"alias_kind":"pith_short_12","alias_value":"5XUJUFPAH2XH","created_at":"2026-05-18T12:27:34Z"},{"alias_kind":"pith_short_16","alias_value":"5XUJUFPAH2XHST6Q","created_at":"2026-05-18T12:27:34Z"},{"alias_kind":"pith_short_8","alias_value":"5XUJUFPA","created_at":"2026-05-18T12:27:34Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:5XUJUFPAH2XHST6QQB7ZIW4ZQI","target":"record","payload":{"canonical_record":{"source":{"id":"1310.2870","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2013-10-10T16:17:59Z","cross_cats_sorted":[],"title_canon_sha256":"a11f8d9a558c499eada964f58a1a7dee068225cf21d07130f67048bb73ad2445","abstract_canon_sha256":"4bef72286e7937f646df4d47c4830fa976d94b460accac7640c9307a1f1051f0"},"schema_version":"1.0"},"canonical_sha256":"ede89a15e03eae794fd0807f945b998216ccd5cffaf2389e7f329f27116cc2aa","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:47:06.874166Z","signature_b64":"W5+99DmoKPtBdhca8i2a2w7eiSs404y7WHx3kwpNAlAPueSNucGW9EyE/fmLd3FtvdRHjOgnSkGfjbnmevDMAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"ede89a15e03eae794fd0807f945b998216ccd5cffaf2389e7f329f27116cc2aa","last_reissued_at":"2026-05-18T01:47:06.873538Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:47:06.873538Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1310.2870","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":"2026-05-18T01:47:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ruYrZR3fQSQk1bCOeCbSSNiKNhgkpFND8KCMxfkRQamRA/BZ73VgkSTCiGUKAoZzJMiaUpGYWF+xF9uOK4HMAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T05:15:01.509010Z"},"content_sha256":"62e100c5b25d43e7be743d3f87fb908473f17de11d1038b17f4990b476ce1f78","schema_version":"1.0","event_id":"sha256:62e100c5b25d43e7be743d3f87fb908473f17de11d1038b17f4990b476ce1f78"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:5XUJUFPAH2XHST6QQB7ZIW4ZQI","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The spectral index image of the radio halo in the cluster Abell 520 hosting a famous bow shock","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"F. Govoni, G. Giovannini, L. Feretti, M. Murgia, R. A. Perley, T. E. Clarke, V. Vacca","submitted_at":"2013-10-10T16:17:59Z","abstract_excerpt":"Synchrotron radio emission is being detected from an increasing number of galaxy clusters. Spectral index images are a powerful tool to investigate the origin, nature, and connection of these sources with the dynamical state of the cluster. The aim of this work is to investigate the spectral index distribution of the radio halo in the galaxy cluster A520, a complex system from an optical, radio, and X-ray point of view. We present deep Very Large Array observations in total intensity at 325 and 1400 MHz. We produced and analyzed spectral index images of the radio halo in this frequency range a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1310.2870","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":""},"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":"2026-05-18T01:47:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Ox43NGd2KlwQPUvSW1782P8qDSOt5voOK9FK47wnX3mwuut0T7xwM/mspB2TyuqvhXXK/YuURBPlKQyruicnBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T05:15:01.509371Z"},"content_sha256":"9a2beda8ffadb6631660d524e7b1c5aff0d6ebd23c0fe18a066bc80904b68614","schema_version":"1.0","event_id":"sha256:9a2beda8ffadb6631660d524e7b1c5aff0d6ebd23c0fe18a066bc80904b68614"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI/bundle.json","state_url":"https://pith.science/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI/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":"2026-06-03T05:15:01Z","links":{"resolver":"https://pith.science/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI","bundle":"https://pith.science/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI/bundle.json","state":"https://pith.science/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI/state.json","well_known_bundle":"https://pith.science/.well-known/pith/5XUJUFPAH2XHST6QQB7ZIW4ZQI/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:5XUJUFPAH2XHST6QQB7ZIW4ZQI","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":"4bef72286e7937f646df4d47c4830fa976d94b460accac7640c9307a1f1051f0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2013-10-10T16:17:59Z","title_canon_sha256":"a11f8d9a558c499eada964f58a1a7dee068225cf21d07130f67048bb73ad2445"},"schema_version":"1.0","source":{"id":"1310.2870","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1310.2870","created_at":"2026-05-18T01:47:06Z"},{"alias_kind":"arxiv_version","alias_value":"1310.2870v1","created_at":"2026-05-18T01:47:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1310.2870","created_at":"2026-05-18T01:47:06Z"},{"alias_kind":"pith_short_12","alias_value":"5XUJUFPAH2XH","created_at":"2026-05-18T12:27:34Z"},{"alias_kind":"pith_short_16","alias_value":"5XUJUFPAH2XHST6Q","created_at":"2026-05-18T12:27:34Z"},{"alias_kind":"pith_short_8","alias_value":"5XUJUFPA","created_at":"2026-05-18T12:27:34Z"}],"graph_snapshots":[{"event_id":"sha256:9a2beda8ffadb6631660d524e7b1c5aff0d6ebd23c0fe18a066bc80904b68614","target":"graph","created_at":"2026-05-18T01:47:06Z","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"},"paper":{"abstract_excerpt":"Synchrotron radio emission is being detected from an increasing number of galaxy clusters. Spectral index images are a powerful tool to investigate the origin, nature, and connection of these sources with the dynamical state of the cluster. The aim of this work is to investigate the spectral index distribution of the radio halo in the galaxy cluster A520, a complex system from an optical, radio, and X-ray point of view. We present deep Very Large Array observations in total intensity at 325 and 1400 MHz. We produced and analyzed spectral index images of the radio halo in this frequency range a","authors_text":"F. Govoni, G. Giovannini, L. Feretti, M. Murgia, R. A. Perley, T. E. Clarke, V. Vacca","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2013-10-10T16:17:59Z","title":"The spectral index image of the radio halo in the cluster Abell 520 hosting a famous bow shock"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1310.2870","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":"sha256:62e100c5b25d43e7be743d3f87fb908473f17de11d1038b17f4990b476ce1f78","target":"record","created_at":"2026-05-18T01:47:06Z","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":"4bef72286e7937f646df4d47c4830fa976d94b460accac7640c9307a1f1051f0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2013-10-10T16:17:59Z","title_canon_sha256":"a11f8d9a558c499eada964f58a1a7dee068225cf21d07130f67048bb73ad2445"},"schema_version":"1.0","source":{"id":"1310.2870","kind":"arxiv","version":1}},"canonical_sha256":"ede89a15e03eae794fd0807f945b998216ccd5cffaf2389e7f329f27116cc2aa","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"ede89a15e03eae794fd0807f945b998216ccd5cffaf2389e7f329f27116cc2aa","first_computed_at":"2026-05-18T01:47:06.873538Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:47:06.873538Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"W5+99DmoKPtBdhca8i2a2w7eiSs404y7WHx3kwpNAlAPueSNucGW9EyE/fmLd3FtvdRHjOgnSkGfjbnmevDMAg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:47:06.874166Z","signed_message":"canonical_sha256_bytes"},"source_id":"1310.2870","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:62e100c5b25d43e7be743d3f87fb908473f17de11d1038b17f4990b476ce1f78","sha256:9a2beda8ffadb6631660d524e7b1c5aff0d6ebd23c0fe18a066bc80904b68614"],"state_sha256":"20f41f8850acfd227d7720380164c00fa11f8b76152582da0b9b12e8cf6e2020"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QHSG1bgvTbjxXZ4y8A7tp/BJKxYk2dwtaLIR+e8I/N3PQ4TYJQ2Bv+nvlGV2fXjwstNYz91GFpg1/dtywus3Bw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T05:15:01.511525Z","bundle_sha256":"4736e10154654df13cdcc60b8ec80b37405f55570eead33a1f258d2a9d97c84f"}}