{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:GYU5DSC2VEEKE3XSABU64ERFYF","short_pith_number":"pith:GYU5DSC2","canonical_record":{"source":{"id":"1807.04928","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-07-13T06:17:34Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"b74304a723141b76759be4e800144534e3e67e82cc1cc8ca1e93a7fe824fc5a5","abstract_canon_sha256":"ca286b1f24fe31b7536ca4cd4ffb2b8e22451058025e3c8f3d5b69e6c27d662d"},"schema_version":"1.0"},"canonical_sha256":"3629d1c85aa908a26ef20069ee1225c1758a23c30415311677701813e0275fe0","source":{"kind":"arxiv","id":"1807.04928","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.04928","created_at":"2026-05-18T00:04:55Z"},{"alias_kind":"arxiv_version","alias_value":"1807.04928v1","created_at":"2026-05-18T00:04:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.04928","created_at":"2026-05-18T00:04:55Z"},{"alias_kind":"pith_short_12","alias_value":"GYU5DSC2VEEK","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_16","alias_value":"GYU5DSC2VEEKE3XS","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_8","alias_value":"GYU5DSC2","created_at":"2026-05-18T12:32:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:GYU5DSC2VEEKE3XSABU64ERFYF","target":"record","payload":{"canonical_record":{"source":{"id":"1807.04928","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-07-13T06:17:34Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"b74304a723141b76759be4e800144534e3e67e82cc1cc8ca1e93a7fe824fc5a5","abstract_canon_sha256":"ca286b1f24fe31b7536ca4cd4ffb2b8e22451058025e3c8f3d5b69e6c27d662d"},"schema_version":"1.0"},"canonical_sha256":"3629d1c85aa908a26ef20069ee1225c1758a23c30415311677701813e0275fe0","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:04:55.489145Z","signature_b64":"51NUC6kOzELfVzpA3FtcOU7vrlPTAr100Sgi7twwFyW+iNhQsFUootBIuTOXHMKRAtbF0QGTy1bq+rAcimUSDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"3629d1c85aa908a26ef20069ee1225c1758a23c30415311677701813e0275fe0","last_reissued_at":"2026-05-18T00:04:55.488655Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:04:55.488655Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1807.04928","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":"2026-05-18T00:04:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"eVGMAsbARPuxbnlYVd/lGZqlMr6VKkVXDG6DQsd2aL0uCYIyi6l4wSfkiaqORyf7QWOjdp87t9qYGS+6nFb5Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T18:18:44.854915Z"},"content_sha256":"ec312e68054f99f45a70c7a7f7c2b84b86e8659fc3665400b2949b226096defc","schema_version":"1.0","event_id":"sha256:ec312e68054f99f45a70c7a7f7c2b84b86e8659fc3665400b2949b226096defc"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:GYU5DSC2VEEKE3XSABU64ERFYF","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Classifying AGN by X-ray Hardness Variability","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.GA","authors_text":"Ehud Behar, Uria Peretz","submitted_at":"2018-07-13T06:17:34Z","abstract_excerpt":"The physics behind the dramatic and unpredictable X-ray variability of Active Galactic Nuclei (AGN) has eluded astronomers since it was discovered. We present an analysis of Swift XRT observations of 44 AGN with at least 20 Swift observations. We define HR-slope as the change of Hardness Ratio (HR) with luminosity ($L$). This slope is measured for all objects in order to: 1. Classify different AGN according to their HR-HR-slope relation and 2. compare HR-$L/L_\\mathrm{Edd}$ trends with those observed in X-ray binaries for the 27 AGN with well measured black hole masses. We compare results using"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.04928","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":"2026-05-18T00:04:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Hm3OwLkOBQ/KRI+gZzHhSpUjpFgb1x9b6e9wuP/BF/D2oC03Vni4FMLOX6rzBEIN52OejnDHq1v+t+yqFMMVDg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T18:18:44.855524Z"},"content_sha256":"3217e62eaee08423f04711307a34a2b08e4a266f5d9e16fa779321a0fa5cb393","schema_version":"1.0","event_id":"sha256:3217e62eaee08423f04711307a34a2b08e4a266f5d9e16fa779321a0fa5cb393"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/GYU5DSC2VEEKE3XSABU64ERFYF/bundle.json","state_url":"https://pith.science/pith/GYU5DSC2VEEKE3XSABU64ERFYF/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/GYU5DSC2VEEKE3XSABU64ERFYF/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":"2026-05-31T18:18:44Z","links":{"resolver":"https://pith.science/pith/GYU5DSC2VEEKE3XSABU64ERFYF","bundle":"https://pith.science/pith/GYU5DSC2VEEKE3XSABU64ERFYF/bundle.json","state":"https://pith.science/pith/GYU5DSC2VEEKE3XSABU64ERFYF/state.json","well_known_bundle":"https://pith.science/.well-known/pith/GYU5DSC2VEEKE3XSABU64ERFYF/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:GYU5DSC2VEEKE3XSABU64ERFYF","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":"ca286b1f24fe31b7536ca4cd4ffb2b8e22451058025e3c8f3d5b69e6c27d662d","cross_cats_sorted":["astro-ph.HE"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-07-13T06:17:34Z","title_canon_sha256":"b74304a723141b76759be4e800144534e3e67e82cc1cc8ca1e93a7fe824fc5a5"},"schema_version":"1.0","source":{"id":"1807.04928","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1807.04928","created_at":"2026-05-18T00:04:55Z"},{"alias_kind":"arxiv_version","alias_value":"1807.04928v1","created_at":"2026-05-18T00:04:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1807.04928","created_at":"2026-05-18T00:04:55Z"},{"alias_kind":"pith_short_12","alias_value":"GYU5DSC2VEEK","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_16","alias_value":"GYU5DSC2VEEKE3XS","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_8","alias_value":"GYU5DSC2","created_at":"2026-05-18T12:32:25Z"}],"graph_snapshots":[{"event_id":"sha256:3217e62eaee08423f04711307a34a2b08e4a266f5d9e16fa779321a0fa5cb393","target":"graph","created_at":"2026-05-18T00:04:55Z","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":"The physics behind the dramatic and unpredictable X-ray variability of Active Galactic Nuclei (AGN) has eluded astronomers since it was discovered. We present an analysis of Swift XRT observations of 44 AGN with at least 20 Swift observations. We define HR-slope as the change of Hardness Ratio (HR) with luminosity ($L$). This slope is measured for all objects in order to: 1. Classify different AGN according to their HR-HR-slope relation and 2. compare HR-$L/L_\\mathrm{Edd}$ trends with those observed in X-ray binaries for the 27 AGN with well measured black hole masses. We compare results using","authors_text":"Ehud Behar, Uria Peretz","cross_cats":["astro-ph.HE"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-07-13T06:17:34Z","title":"Classifying AGN by X-ray Hardness Variability"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1807.04928","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:ec312e68054f99f45a70c7a7f7c2b84b86e8659fc3665400b2949b226096defc","target":"record","created_at":"2026-05-18T00:04:55Z","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":"ca286b1f24fe31b7536ca4cd4ffb2b8e22451058025e3c8f3d5b69e6c27d662d","cross_cats_sorted":["astro-ph.HE"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-07-13T06:17:34Z","title_canon_sha256":"b74304a723141b76759be4e800144534e3e67e82cc1cc8ca1e93a7fe824fc5a5"},"schema_version":"1.0","source":{"id":"1807.04928","kind":"arxiv","version":1}},"canonical_sha256":"3629d1c85aa908a26ef20069ee1225c1758a23c30415311677701813e0275fe0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"3629d1c85aa908a26ef20069ee1225c1758a23c30415311677701813e0275fe0","first_computed_at":"2026-05-18T00:04:55.488655Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:04:55.488655Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"51NUC6kOzELfVzpA3FtcOU7vrlPTAr100Sgi7twwFyW+iNhQsFUootBIuTOXHMKRAtbF0QGTy1bq+rAcimUSDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:04:55.489145Z","signed_message":"canonical_sha256_bytes"},"source_id":"1807.04928","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ec312e68054f99f45a70c7a7f7c2b84b86e8659fc3665400b2949b226096defc","sha256:3217e62eaee08423f04711307a34a2b08e4a266f5d9e16fa779321a0fa5cb393"],"state_sha256":"09aede0881cf006a1b6c3091ba5d779eb2f9128f169d9ed5276e8fa5ac8420df"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Gd6cpCOQvPk3SuiFycc81MzYj/JKuSTM97FIKw6oYP1vm85rOoNZcl11P1Xs2CwYjepI3b2zeXbbbEnwrTf2Dg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T18:18:44.858104Z","bundle_sha256":"88f9a45750f15e586725504dacbc81451fef2b8e264bb03c728d5057f8bc880a"}}