{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:HKLY7NV2PZ4FGCXVJ2RN6ZB2CH","short_pith_number":"pith:HKLY7NV2","canonical_record":{"source":{"id":"1501.06631","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2015-01-27T01:08:18Z","cross_cats_sorted":[],"title_canon_sha256":"f1e72a916b1acd0a6448aee09fe2fce210928ebb38163d68ddc5f481a17b4b41","abstract_canon_sha256":"ad68a4e3782fb99e1f7d220e69f05ba707a62c7f235e8e0cf6b8ce9e7984c35d"},"schema_version":"1.0"},"canonical_sha256":"3a978fb6ba7e78530af54ea2df643a11f1bf69585f6c39d70e0c0a1340d361f6","source":{"kind":"arxiv","id":"1501.06631","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1501.06631","created_at":"2026-05-18T01:41:06Z"},{"alias_kind":"arxiv_version","alias_value":"1501.06631v1","created_at":"2026-05-18T01:41:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1501.06631","created_at":"2026-05-18T01:41:06Z"},{"alias_kind":"pith_short_12","alias_value":"HKLY7NV2PZ4F","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_16","alias_value":"HKLY7NV2PZ4FGCXV","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_8","alias_value":"HKLY7NV2","created_at":"2026-05-18T12:29:25Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:HKLY7NV2PZ4FGCXVJ2RN6ZB2CH","target":"record","payload":{"canonical_record":{"source":{"id":"1501.06631","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2015-01-27T01:08:18Z","cross_cats_sorted":[],"title_canon_sha256":"f1e72a916b1acd0a6448aee09fe2fce210928ebb38163d68ddc5f481a17b4b41","abstract_canon_sha256":"ad68a4e3782fb99e1f7d220e69f05ba707a62c7f235e8e0cf6b8ce9e7984c35d"},"schema_version":"1.0"},"canonical_sha256":"3a978fb6ba7e78530af54ea2df643a11f1bf69585f6c39d70e0c0a1340d361f6","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:41:06.472202Z","signature_b64":"TqtnUTc5pbgFbhpPFjsec//eKshemBR22dsBu23mtfj0J1g+g9UjtJMpMkg8USKMTvqXS+mplkDGpojEi0FXDg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"3a978fb6ba7e78530af54ea2df643a11f1bf69585f6c39d70e0c0a1340d361f6","last_reissued_at":"2026-05-18T01:41:06.471482Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:41:06.471482Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1501.06631","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":"2026-05-18T01:41:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"oSGNjzucn+inye6l/kIFDhXUSYCEJMstLwIZwl28elNtJUXdRG/NW7kBz4dFnNGNgwig0L1jG2eMwjo6Gs2aBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T20:18:14.469984Z"},"content_sha256":"952d3446d929187d1f11aa17047d40336f7cbab0e45ec397785e8e02dfa00ba3","schema_version":"1.0","event_id":"sha256:952d3446d929187d1f11aa17047d40336f7cbab0e45ec397785e8e02dfa00ba3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:HKLY7NV2PZ4FGCXVJ2RN6ZB2CH","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Tracing the Metal-Poor M31 Stellar Halo with Blue Horizontal Branch Stars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Anil C. Seth, Benjamin F. Williams, Claire Dorman, Eric F. BellKaroline M. Gilbert, Jason S. Kalirai, Julianne J. Dalcanton, Leo Girardi, Philip Rosenfield, Puragra Guhathakurta, Tod R. Lauer","submitted_at":"2015-01-27T01:08:18Z","abstract_excerpt":"We have analyzed new HST/ACS and HST/WFC3 imaging in F475W and F814W of two previously-unobserved fields along the M31 minor axis to confirm our previous constraints on the shape of M31's inner stellar halo. Both of these new datasets reach a depth of at least F814W$<$27 and clearly detect the blue horizontal branch (BHB) of the field as a distinct feature of the color-magnitude diagram. We measure the density of BHB stars and the ratio of BHB to red giant branch stars in each field using identical techniques to our previous work. We find excellent agreement with our previous measurement of a "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1501.06631","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":"2026-05-18T01:41:06Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"gTudwqOARNe8T51ZVoP0HZuTxrHRnR9p6fWMGAa8QGYOnOp2tyZJ4PmzIsvqwKlhGWSsuWHhqY9kH8Ki7zt7Cw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T20:18:14.470592Z"},"content_sha256":"c290aa17a6245db40b89ab9dcca7dbfd1091bf5d792d148f489ff2ff2ecab7f9","schema_version":"1.0","event_id":"sha256:c290aa17a6245db40b89ab9dcca7dbfd1091bf5d792d148f489ff2ff2ecab7f9"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH/bundle.json","state_url":"https://pith.science/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH/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":"2026-05-27T20:18:14Z","links":{"resolver":"https://pith.science/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH","bundle":"https://pith.science/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH/bundle.json","state":"https://pith.science/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH/state.json","well_known_bundle":"https://pith.science/.well-known/pith/HKLY7NV2PZ4FGCXVJ2RN6ZB2CH/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:HKLY7NV2PZ4FGCXVJ2RN6ZB2CH","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":"ad68a4e3782fb99e1f7d220e69f05ba707a62c7f235e8e0cf6b8ce9e7984c35d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2015-01-27T01:08:18Z","title_canon_sha256":"f1e72a916b1acd0a6448aee09fe2fce210928ebb38163d68ddc5f481a17b4b41"},"schema_version":"1.0","source":{"id":"1501.06631","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1501.06631","created_at":"2026-05-18T01:41:06Z"},{"alias_kind":"arxiv_version","alias_value":"1501.06631v1","created_at":"2026-05-18T01:41:06Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1501.06631","created_at":"2026-05-18T01:41:06Z"},{"alias_kind":"pith_short_12","alias_value":"HKLY7NV2PZ4F","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_16","alias_value":"HKLY7NV2PZ4FGCXV","created_at":"2026-05-18T12:29:25Z"},{"alias_kind":"pith_short_8","alias_value":"HKLY7NV2","created_at":"2026-05-18T12:29:25Z"}],"graph_snapshots":[{"event_id":"sha256:c290aa17a6245db40b89ab9dcca7dbfd1091bf5d792d148f489ff2ff2ecab7f9","target":"graph","created_at":"2026-05-18T01:41:06Z","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":"We have analyzed new HST/ACS and HST/WFC3 imaging in F475W and F814W of two previously-unobserved fields along the M31 minor axis to confirm our previous constraints on the shape of M31's inner stellar halo. Both of these new datasets reach a depth of at least F814W$<$27 and clearly detect the blue horizontal branch (BHB) of the field as a distinct feature of the color-magnitude diagram. We measure the density of BHB stars and the ratio of BHB to red giant branch stars in each field using identical techniques to our previous work. We find excellent agreement with our previous measurement of a ","authors_text":"Anil C. Seth, Benjamin F. Williams, Claire Dorman, Eric F. BellKaroline M. Gilbert, Jason S. Kalirai, Julianne J. Dalcanton, Leo Girardi, Philip Rosenfield, Puragra Guhathakurta, Tod R. Lauer","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2015-01-27T01:08:18Z","title":"Tracing the Metal-Poor M31 Stellar Halo with Blue Horizontal Branch Stars"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1501.06631","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":"sha256:952d3446d929187d1f11aa17047d40336f7cbab0e45ec397785e8e02dfa00ba3","target":"record","created_at":"2026-05-18T01:41:06Z","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":"ad68a4e3782fb99e1f7d220e69f05ba707a62c7f235e8e0cf6b8ce9e7984c35d","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2015-01-27T01:08:18Z","title_canon_sha256":"f1e72a916b1acd0a6448aee09fe2fce210928ebb38163d68ddc5f481a17b4b41"},"schema_version":"1.0","source":{"id":"1501.06631","kind":"arxiv","version":1}},"canonical_sha256":"3a978fb6ba7e78530af54ea2df643a11f1bf69585f6c39d70e0c0a1340d361f6","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"3a978fb6ba7e78530af54ea2df643a11f1bf69585f6c39d70e0c0a1340d361f6","first_computed_at":"2026-05-18T01:41:06.471482Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:41:06.471482Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"TqtnUTc5pbgFbhpPFjsec//eKshemBR22dsBu23mtfj0J1g+g9UjtJMpMkg8USKMTvqXS+mplkDGpojEi0FXDg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:41:06.472202Z","signed_message":"canonical_sha256_bytes"},"source_id":"1501.06631","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:952d3446d929187d1f11aa17047d40336f7cbab0e45ec397785e8e02dfa00ba3","sha256:c290aa17a6245db40b89ab9dcca7dbfd1091bf5d792d148f489ff2ff2ecab7f9"],"state_sha256":"fec5fdb8994e84323c3fb1b2be6ea539ab19585d6c014621bf6597a311c71933"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"hEZsqlhfdgIVjRIpTwM/iV09Lr7szqBQUdT0H2mzavIkMhtuSmxHgreiXi9RJD0SkVED+nLXRz0vF2bLGX8pDg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T20:18:14.473825Z","bundle_sha256":"418a95e6be0167560ce60158987ba38f8fadad0d8b105475e8b96236a83dccba"}}