{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:GULW7HXYKRJZ2G4UWYCYFDJ44Q","short_pith_number":"pith:GULW7HXY","canonical_record":{"source":{"id":"1810.06616","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-10-15T19:02:35Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"3e56e369062e52e9fac42f9f869eff00bd37ced59a470aba1af8afea8cf41ba0","abstract_canon_sha256":"f7e57cd0e7cc8cf6a5b595aa24596d7d53853377d1ab5ad0e25358b2643c709e"},"schema_version":"1.0"},"canonical_sha256":"35176f9ef854539d1b94b605828d3ce42e268213b3cfd51f9b135eb3dadedbd3","source":{"kind":"arxiv","id":"1810.06616","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1810.06616","created_at":"2026-05-18T00:00:47Z"},{"alias_kind":"arxiv_version","alias_value":"1810.06616v1","created_at":"2026-05-18T00:00:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1810.06616","created_at":"2026-05-18T00:00:47Z"},{"alias_kind":"pith_short_12","alias_value":"GULW7HXYKRJZ","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_16","alias_value":"GULW7HXYKRJZ2G4U","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_8","alias_value":"GULW7HXY","created_at":"2026-05-18T12:32:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:GULW7HXYKRJZ2G4UWYCYFDJ44Q","target":"record","payload":{"canonical_record":{"source":{"id":"1810.06616","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-10-15T19:02:35Z","cross_cats_sorted":["astro-ph.HE"],"title_canon_sha256":"3e56e369062e52e9fac42f9f869eff00bd37ced59a470aba1af8afea8cf41ba0","abstract_canon_sha256":"f7e57cd0e7cc8cf6a5b595aa24596d7d53853377d1ab5ad0e25358b2643c709e"},"schema_version":"1.0"},"canonical_sha256":"35176f9ef854539d1b94b605828d3ce42e268213b3cfd51f9b135eb3dadedbd3","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:00:47.291956Z","signature_b64":"MGaDk3vZrOe82xbjhMT39w9tW3eRlp5KDNOjJsf5jddeVZcFwX2PWZ6lpVlfiy39lXE5Qs1KhF/J2E8YOHHnAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"35176f9ef854539d1b94b605828d3ce42e268213b3cfd51f9b135eb3dadedbd3","last_reissued_at":"2026-05-18T00:00:47.291286Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:00:47.291286Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1810.06616","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":"2026-05-18T00:00:47Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4HCH87O5A87ahrPzk5o1MBrJHVHRlgx9PS3Y/5t6ilI1tjOnOmspo24URwwagMebplL/dtOOv42kmRTwcl0BCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T04:14:12.475052Z"},"content_sha256":"7f240e4e8e52577f736f22260ea965f338aa6b62799c77939988895a379a0930","schema_version":"1.0","event_id":"sha256:7f240e4e8e52577f736f22260ea965f338aa6b62799c77939988895a379a0930"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:GULW7HXYKRJZ2G4UWYCYFDJ44Q","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Changing-Look Quasar Mrk 590 is Awakening","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.GA","authors_text":"A. Gupta, B. M. Peterson, F. Nicastro, G. De Rosa, J. Collinson, K.D. Denney, K. Korista, M. Goad, M. Vestergaard, R.W. Pogge, S. Mathur, Y. Krongold","submitted_at":"2018-10-15T19:02:35Z","abstract_excerpt":"Mrk 590 was originally classified as a Seyfert 1 galaxy, but then it underwent dramatic changes: the nuclear luminosity dropped by over two orders of magnitude and the broad emission lines all but disappeared from the optical spectrum. Here we present followup observations to the original discovery and characterization of this \"changing look\" active galactic nucleus (AGN). The new Chandra and HST observations from 2014 show that Mrk 590 is awakening, changing its appearance again. While the source continues to be in a low state, its soft excess has re-emerged, though not to the previous level."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.06616","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":"2026-05-18T00:00:47Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"z+VRfdFqkvvURm5Qp6/dHBn3YIIH0d3l83Z+wbr3/2O+YhOpEUHcuDbRkjDp0X52Iu4H9pH5kG0mcY7krjODDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T04:14:12.475725Z"},"content_sha256":"2c29b4da6c32993ac0c2210cb7f2cd423d0b251479728ec7d162e91dc3054aaf","schema_version":"1.0","event_id":"sha256:2c29b4da6c32993ac0c2210cb7f2cd423d0b251479728ec7d162e91dc3054aaf"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q/bundle.json","state_url":"https://pith.science/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q/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":"2026-05-26T04:14:12Z","links":{"resolver":"https://pith.science/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q","bundle":"https://pith.science/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q/bundle.json","state":"https://pith.science/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q/state.json","well_known_bundle":"https://pith.science/.well-known/pith/GULW7HXYKRJZ2G4UWYCYFDJ44Q/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:GULW7HXYKRJZ2G4UWYCYFDJ44Q","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":"f7e57cd0e7cc8cf6a5b595aa24596d7d53853377d1ab5ad0e25358b2643c709e","cross_cats_sorted":["astro-ph.HE"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-10-15T19:02:35Z","title_canon_sha256":"3e56e369062e52e9fac42f9f869eff00bd37ced59a470aba1af8afea8cf41ba0"},"schema_version":"1.0","source":{"id":"1810.06616","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1810.06616","created_at":"2026-05-18T00:00:47Z"},{"alias_kind":"arxiv_version","alias_value":"1810.06616v1","created_at":"2026-05-18T00:00:47Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1810.06616","created_at":"2026-05-18T00:00:47Z"},{"alias_kind":"pith_short_12","alias_value":"GULW7HXYKRJZ","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_16","alias_value":"GULW7HXYKRJZ2G4U","created_at":"2026-05-18T12:32:25Z"},{"alias_kind":"pith_short_8","alias_value":"GULW7HXY","created_at":"2026-05-18T12:32:25Z"}],"graph_snapshots":[{"event_id":"sha256:2c29b4da6c32993ac0c2210cb7f2cd423d0b251479728ec7d162e91dc3054aaf","target":"graph","created_at":"2026-05-18T00:00:47Z","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":"Mrk 590 was originally classified as a Seyfert 1 galaxy, but then it underwent dramatic changes: the nuclear luminosity dropped by over two orders of magnitude and the broad emission lines all but disappeared from the optical spectrum. Here we present followup observations to the original discovery and characterization of this \"changing look\" active galactic nucleus (AGN). The new Chandra and HST observations from 2014 show that Mrk 590 is awakening, changing its appearance again. While the source continues to be in a low state, its soft excess has re-emerged, though not to the previous level.","authors_text":"A. Gupta, B. M. Peterson, F. Nicastro, G. De Rosa, J. Collinson, K.D. Denney, K. Korista, M. Goad, M. Vestergaard, R.W. Pogge, S. Mathur, Y. Krongold","cross_cats":["astro-ph.HE"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-10-15T19:02:35Z","title":"The Changing-Look Quasar Mrk 590 is Awakening"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.06616","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":"sha256:7f240e4e8e52577f736f22260ea965f338aa6b62799c77939988895a379a0930","target":"record","created_at":"2026-05-18T00:00:47Z","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":"f7e57cd0e7cc8cf6a5b595aa24596d7d53853377d1ab5ad0e25358b2643c709e","cross_cats_sorted":["astro-ph.HE"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2018-10-15T19:02:35Z","title_canon_sha256":"3e56e369062e52e9fac42f9f869eff00bd37ced59a470aba1af8afea8cf41ba0"},"schema_version":"1.0","source":{"id":"1810.06616","kind":"arxiv","version":1}},"canonical_sha256":"35176f9ef854539d1b94b605828d3ce42e268213b3cfd51f9b135eb3dadedbd3","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"35176f9ef854539d1b94b605828d3ce42e268213b3cfd51f9b135eb3dadedbd3","first_computed_at":"2026-05-18T00:00:47.291286Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:00:47.291286Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"MGaDk3vZrOe82xbjhMT39w9tW3eRlp5KDNOjJsf5jddeVZcFwX2PWZ6lpVlfiy39lXE5Qs1KhF/J2E8YOHHnAw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:00:47.291956Z","signed_message":"canonical_sha256_bytes"},"source_id":"1810.06616","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:7f240e4e8e52577f736f22260ea965f338aa6b62799c77939988895a379a0930","sha256:2c29b4da6c32993ac0c2210cb7f2cd423d0b251479728ec7d162e91dc3054aaf"],"state_sha256":"980419dbf087f3edd8d2ec4e89f9f163c3ba2ae106fae1b3b4c04cc607a6da25"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bJHmitP4EhcohIgyLnGDZNIdzZATlts4vh1jO1Q9J/g1lBcTe3w06FDVuViolcjQB7YELagn3Cy3p3lRRu6nDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T04:14:12.479281Z","bundle_sha256":"f4e9ba1fe305d74fef524eb3eb8835c2b0e48791f9d184a8aed67af0425cc353"}}