{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:K3KWUMLB6C5YRSKMP4JQYN2L5J","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":"6d9958e54afec0aff0ae96a27e6bdbc7e6725399955eb8fc7cb1de82ceb570de","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2018-08-01T19:01:11Z","title_canon_sha256":"ee4961cd83738ffdb989a84d4301086b83c3ba57ee6f089d1ddb25fb94b2d435"},"schema_version":"1.0","source":{"id":"1808.00510","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1808.00510","created_at":"2026-05-17T23:55:20Z"},{"alias_kind":"arxiv_version","alias_value":"1808.00510v2","created_at":"2026-05-17T23:55:20Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1808.00510","created_at":"2026-05-17T23:55:20Z"},{"alias_kind":"pith_short_12","alias_value":"K3KWUMLB6C5Y","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_16","alias_value":"K3KWUMLB6C5YRSKM","created_at":"2026-05-18T12:32:33Z"},{"alias_kind":"pith_short_8","alias_value":"K3KWUMLB","created_at":"2026-05-18T12:32:33Z"}],"graph_snapshots":[{"event_id":"sha256:76a10c8edfa42ed86514115a358c0ca5f658ae0ce1b3f3daa2e15efc25c79f77","target":"graph","created_at":"2026-05-17T23:55:20Z","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":"We study the spectroscopic evolution of superluminous supernovae (SLSNe) later than 100 days after maximum light. We present new data for Gaia16apd and SN2017egm, and analyse these with a larger sample comprising 41 spectra of 12 events. The spectra become nebular within 2-4 $e$-folding times after light curve peak, with the rate of spectroscopic evolution correlated to the light curve timescale. Emission lines are identified with well-known transitions of oxygen, calcium, magnesium, sodium and iron. SLSNe are differentiated from other Type Ic SNe by a prominent O I $\\lambda$7774 line and high","authors_text":"Edo Berger, Matt Nicholl, Peter K Blanchard, Ryan Chornock, Sebastian Gomez","cross_cats":["astro-ph.SR"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2018-08-01T19:01:11Z","title":"Nebular-phase spectra of superluminous supernovae: physical insights from observational and statistical properties"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1808.00510","kind":"arxiv","version":2},"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":"sha256:42d48a09b29deff1641a117a620817d57f8f376190a5f92def07c7969244dd5f","target":"record","created_at":"2026-05-17T23:55:20Z","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":"6d9958e54afec0aff0ae96a27e6bdbc7e6725399955eb8fc7cb1de82ceb570de","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2018-08-01T19:01:11Z","title_canon_sha256":"ee4961cd83738ffdb989a84d4301086b83c3ba57ee6f089d1ddb25fb94b2d435"},"schema_version":"1.0","source":{"id":"1808.00510","kind":"arxiv","version":2}},"canonical_sha256":"56d56a3161f0bb88c94c7f130c374bea5f6195298f669c52ed2303ada5d7deec","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"56d56a3161f0bb88c94c7f130c374bea5f6195298f669c52ed2303ada5d7deec","first_computed_at":"2026-05-17T23:55:20.207343Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:55:20.207343Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"qFsAAacXHYJXFmacqCcuswHJ3VCPFQrC1Ga/GfxsOqR1vv7TEZOB8yqVW/s18D4CRe1n8AqKIb7v/UVo7R3pCA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:55:20.207945Z","signed_message":"canonical_sha256_bytes"},"source_id":"1808.00510","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:42d48a09b29deff1641a117a620817d57f8f376190a5f92def07c7969244dd5f","sha256:76a10c8edfa42ed86514115a358c0ca5f658ae0ce1b3f3daa2e15efc25c79f77"],"state_sha256":"406f40dada10acd19cdf3ef9f4a61c400e89cb16a8845df027b9c15eb00a6cb7"}