{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2007:6AOREW76U6CXTKSHZZDN2XARI2","short_pith_number":"pith:6AOREW76","canonical_record":{"source":{"id":"0712.0416","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2007-12-04T00:46:48Z","cross_cats_sorted":[],"title_canon_sha256":"abb8091ba0351bb2a5ad695cbc61a0181e088ecbbfb63baea929c6d577b82e8c","abstract_canon_sha256":"5c696bca11868365d457078291001a8553b4011e5a584f8afd3c74ae52e57946"},"schema_version":"1.0"},"canonical_sha256":"f01d125bfea78579aa47ce46dd5c11468a9dca2cb759ed3e518e3c4f1abbeb61","source":{"kind":"arxiv","id":"0712.0416","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0712.0416","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"arxiv_version","alias_value":"0712.0416v2","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0712.0416","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"pith_short_12","alias_value":"6AOREW76U6CX","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"pith_short_16","alias_value":"6AOREW76U6CXTKSH","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"pith_short_8","alias_value":"6AOREW76","created_at":"2026-07-04T17:07:04Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2007:6AOREW76U6CXTKSHZZDN2XARI2","target":"record","payload":{"canonical_record":{"source":{"id":"0712.0416","kind":"arxiv","version":2},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2007-12-04T00:46:48Z","cross_cats_sorted":[],"title_canon_sha256":"abb8091ba0351bb2a5ad695cbc61a0181e088ecbbfb63baea929c6d577b82e8c","abstract_canon_sha256":"5c696bca11868365d457078291001a8553b4011e5a584f8afd3c74ae52e57946"},"schema_version":"1.0"},"canonical_sha256":"f01d125bfea78579aa47ce46dd5c11468a9dca2cb759ed3e518e3c4f1abbeb61","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-04T17:07:04.667843Z","signature_b64":"6XC+K5tPkwga48MRQhrKnGNd+GURK1pGNubzWLGGu8Z4r3dVV5TTDWV4WDslXLTWpwYFaXF0WJfqAISaxlVfAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"f01d125bfea78579aa47ce46dd5c11468a9dca2cb759ed3e518e3c4f1abbeb61","last_reissued_at":"2026-07-04T17:07:04.667472Z","signature_status":"signed_v1","first_computed_at":"2026-07-04T17:07:04.667472Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0712.0416","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-04T17:07:04Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WfHPK6z7COjcGXb96j8RX5MCv+8j2MoS04RozO7qrRMY3v4nEoPEWa3KPtHCtspX13wSzpALrtugl70yrmXsBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-10T08:44:28.529832Z"},"content_sha256":"786204f02c32ded4f721d218b3c82cba2dee377ff0095846e134bf384650dccb","schema_version":"1.0","event_id":"sha256:786204f02c32ded4f721d218b3c82cba2dee377ff0095846e134bf384650dccb"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2007:6AOREW76U6CXTKSHZZDN2XARI2","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"J. Silk, R. A. Windhorst, R. E. Ryan, S. H. Cohen","submitted_at":"2007-12-04T00:46:48Z","abstract_excerpt":"We present a measurement of the galaxy merger fraction and number density from observations in the Hubble Ultra Deep Field for 0.5<z<2.5. We fit the combination of broadband data and slitless spectroscopy of 1308 galaxies with stellar population synthesis models to select merging systems based on a stellar mass of >10^10 M_sol. When correcting for mass incompleteness, the major merger fraction is not simply proportional to (1+z)^m, but appears to peak at z_frac~=1.3+-0.4. From this merger fraction, we infer that ~42% of massive galaxies have undergone a major merger since z~1. We show that the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0712.0416","kind":"arxiv","version":2},"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/0712.0416/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":"2026-07-04T17:07:04Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hinusET2tK07PKo+Gw44Q4KKlrwGcxT3PB/fdXT9K2Mk6zieEXcRtKW0j9nMrA3CMfva4o5BqOz4XmZoubVeAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-10T08:44:28.530211Z"},"content_sha256":"f9c02e89f7edf7768a873508e115c8199602768f55f9159803420e8a8a0cd55d","schema_version":"1.0","event_id":"sha256:f9c02e89f7edf7768a873508e115c8199602768f55f9159803420e8a8a0cd55d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/6AOREW76U6CXTKSHZZDN2XARI2/bundle.json","state_url":"https://pith.science/pith/6AOREW76U6CXTKSHZZDN2XARI2/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/6AOREW76U6CXTKSHZZDN2XARI2/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":"2026-07-10T08:44:28Z","links":{"resolver":"https://pith.science/pith/6AOREW76U6CXTKSHZZDN2XARI2","bundle":"https://pith.science/pith/6AOREW76U6CXTKSHZZDN2XARI2/bundle.json","state":"https://pith.science/pith/6AOREW76U6CXTKSHZZDN2XARI2/state.json","well_known_bundle":"https://pith.science/.well-known/pith/6AOREW76U6CXTKSHZZDN2XARI2/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2007:6AOREW76U6CXTKSHZZDN2XARI2","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":"5c696bca11868365d457078291001a8553b4011e5a584f8afd3c74ae52e57946","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2007-12-04T00:46:48Z","title_canon_sha256":"abb8091ba0351bb2a5ad695cbc61a0181e088ecbbfb63baea929c6d577b82e8c"},"schema_version":"1.0","source":{"id":"0712.0416","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0712.0416","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"arxiv_version","alias_value":"0712.0416v2","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0712.0416","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"pith_short_12","alias_value":"6AOREW76U6CX","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"pith_short_16","alias_value":"6AOREW76U6CXTKSH","created_at":"2026-07-04T17:07:04Z"},{"alias_kind":"pith_short_8","alias_value":"6AOREW76","created_at":"2026-07-04T17:07:04Z"}],"graph_snapshots":[{"event_id":"sha256:f9c02e89f7edf7768a873508e115c8199602768f55f9159803420e8a8a0cd55d","target":"graph","created_at":"2026-07-04T17:07:04Z","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/0712.0416/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We present a measurement of the galaxy merger fraction and number density from observations in the Hubble Ultra Deep Field for 0.5<z<2.5. We fit the combination of broadband data and slitless spectroscopy of 1308 galaxies with stellar population synthesis models to select merging systems based on a stellar mass of >10^10 M_sol. When correcting for mass incompleteness, the major merger fraction is not simply proportional to (1+z)^m, but appears to peak at z_frac~=1.3+-0.4. From this merger fraction, we infer that ~42% of massive galaxies have undergone a major merger since z~1. We show that the","authors_text":"J. Silk, R. A. Windhorst, R. E. Ryan, S. H. Cohen","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2007-12-04T00:46:48Z","title":"Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0712.0416","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":"sha256:786204f02c32ded4f721d218b3c82cba2dee377ff0095846e134bf384650dccb","target":"record","created_at":"2026-07-04T17:07:04Z","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":"5c696bca11868365d457078291001a8553b4011e5a584f8afd3c74ae52e57946","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2007-12-04T00:46:48Z","title_canon_sha256":"abb8091ba0351bb2a5ad695cbc61a0181e088ecbbfb63baea929c6d577b82e8c"},"schema_version":"1.0","source":{"id":"0712.0416","kind":"arxiv","version":2}},"canonical_sha256":"f01d125bfea78579aa47ce46dd5c11468a9dca2cb759ed3e518e3c4f1abbeb61","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f01d125bfea78579aa47ce46dd5c11468a9dca2cb759ed3e518e3c4f1abbeb61","first_computed_at":"2026-07-04T17:07:04.667472Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T17:07:04.667472Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"6XC+K5tPkwga48MRQhrKnGNd+GURK1pGNubzWLGGu8Z4r3dVV5TTDWV4WDslXLTWpwYFaXF0WJfqAISaxlVfAQ==","signature_status":"signed_v1","signed_at":"2026-07-04T17:07:04.667843Z","signed_message":"canonical_sha256_bytes"},"source_id":"0712.0416","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:786204f02c32ded4f721d218b3c82cba2dee377ff0095846e134bf384650dccb","sha256:f9c02e89f7edf7768a873508e115c8199602768f55f9159803420e8a8a0cd55d"],"state_sha256":"fa6ebefc7e93bf274705ad0fd0c5d5bba59ba4b571ce19045a9be135b8b18172"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"IolvrWyvxtMgulGymJu2J87Mu2XIBJwWAsW1jyRnAOVYVH458H0iqfl98raiXcSqdLIh8Pv7QBZXN3BHYIxpCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-10T08:44:28.532106Z","bundle_sha256":"184e8a15509334d7b0cfbf66b75f3993743d2ab80eab1320b40176e7c3359768"}}