{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2011:533YWCXDR2ZPOONBKKDJSXNZI5","short_pith_number":"pith:533YWCXD","canonical_record":{"source":{"id":"1109.3861","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-09-18T11:40:13Z","cross_cats_sorted":[],"title_canon_sha256":"cea025a39c2bc445fd39fd67887b518560dfa95d260bad40e7c9b142bdffd9d9","abstract_canon_sha256":"6cd75edecc52fbc50add4719e2aa4f4a9c70d813ee31fd0e0753bf8caae7a015"},"schema_version":"1.0"},"canonical_sha256":"eef78b0ae38eb2f739a15286995db9477ae8205c57f2d066c1af05352ef5ae51","source":{"kind":"arxiv","id":"1109.3861","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1109.3861","created_at":"2026-05-18T02:00:29Z"},{"alias_kind":"arxiv_version","alias_value":"1109.3861v1","created_at":"2026-05-18T02:00:29Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1109.3861","created_at":"2026-05-18T02:00:29Z"},{"alias_kind":"pith_short_12","alias_value":"533YWCXDR2ZP","created_at":"2026-05-18T12:26:20Z"},{"alias_kind":"pith_short_16","alias_value":"533YWCXDR2ZPOONB","created_at":"2026-05-18T12:26:20Z"},{"alias_kind":"pith_short_8","alias_value":"533YWCXD","created_at":"2026-05-18T12:26:20Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2011:533YWCXDR2ZPOONBKKDJSXNZI5","target":"record","payload":{"canonical_record":{"source":{"id":"1109.3861","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-09-18T11:40:13Z","cross_cats_sorted":[],"title_canon_sha256":"cea025a39c2bc445fd39fd67887b518560dfa95d260bad40e7c9b142bdffd9d9","abstract_canon_sha256":"6cd75edecc52fbc50add4719e2aa4f4a9c70d813ee31fd0e0753bf8caae7a015"},"schema_version":"1.0"},"canonical_sha256":"eef78b0ae38eb2f739a15286995db9477ae8205c57f2d066c1af05352ef5ae51","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:00:29.655604Z","signature_b64":"cqA+deAeDOhh9sY+7waxBroLTvt6qsRL+nkyVT6qOdhZuBUzL6Qj126IEfOhJutXkLKl2DzxCWBAdiB+ZKZ8DA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"eef78b0ae38eb2f739a15286995db9477ae8205c57f2d066c1af05352ef5ae51","last_reissued_at":"2026-05-18T02:00:29.655106Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:00:29.655106Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1109.3861","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":"2026-05-18T02:00:29Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sHsiJNHhhUDwnrVwThaEfMUThiGFTF5MAOLyb8qfV6gWlZDgzzFx7lInsYqMiHSDArq/rr2Arlcw0KMYNfEkDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T21:19:26.322247Z"},"content_sha256":"8cb551d6d206d8bd2da598874c296bd51bc5c4d5bd424717cc105f0774303b75","schema_version":"1.0","event_id":"sha256:8cb551d6d206d8bd2da598874c296bd51bc5c4d5bd424717cc105f0774303b75"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2011:533YWCXDR2ZPOONBKKDJSXNZI5","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"TreeCol: a novel approach to estimating column densities in astrophysical simulations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Paul C. Clark, Ralf S. Klessen, Simon C.O. Glover","submitted_at":"2011-09-18T11:40:13Z","abstract_excerpt":"We present TreeCol, a new and efficient tree-based scheme to calculate column densities in numerical simulations. Knowing the column density in any direction at any location in space is a prerequisite for modelling the propagation of radiation through the computational domain. TreeCol therefore forms the basis for a fast, approximate method for modelling the attenuation of radiation within large numerical simulations. It constructs a HEALPix sphere at any desired location and accumulates the column density by walking the tree and by adding up the contributions from all tree nodes whose line of"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1109.3861","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":"2026-05-18T02:00:29Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"UmCILE26OBaQSDIY2+Z67zo8jh7v9V8tBF1Z1BzGz8lxCDapsWmy9g6gWaBz600bhyPtHRQ9woCbaqBSsuuABQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T21:19:26.322811Z"},"content_sha256":"0e2ebd76cdf386bdcf617eea327eb64e338a374405f9d18b3323fa2d0ccea6f9","schema_version":"1.0","event_id":"sha256:0e2ebd76cdf386bdcf617eea327eb64e338a374405f9d18b3323fa2d0ccea6f9"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/533YWCXDR2ZPOONBKKDJSXNZI5/bundle.json","state_url":"https://pith.science/pith/533YWCXDR2ZPOONBKKDJSXNZI5/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/533YWCXDR2ZPOONBKKDJSXNZI5/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":"2026-06-06T21:19:26Z","links":{"resolver":"https://pith.science/pith/533YWCXDR2ZPOONBKKDJSXNZI5","bundle":"https://pith.science/pith/533YWCXDR2ZPOONBKKDJSXNZI5/bundle.json","state":"https://pith.science/pith/533YWCXDR2ZPOONBKKDJSXNZI5/state.json","well_known_bundle":"https://pith.science/.well-known/pith/533YWCXDR2ZPOONBKKDJSXNZI5/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:533YWCXDR2ZPOONBKKDJSXNZI5","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":"6cd75edecc52fbc50add4719e2aa4f4a9c70d813ee31fd0e0753bf8caae7a015","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-09-18T11:40:13Z","title_canon_sha256":"cea025a39c2bc445fd39fd67887b518560dfa95d260bad40e7c9b142bdffd9d9"},"schema_version":"1.0","source":{"id":"1109.3861","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1109.3861","created_at":"2026-05-18T02:00:29Z"},{"alias_kind":"arxiv_version","alias_value":"1109.3861v1","created_at":"2026-05-18T02:00:29Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1109.3861","created_at":"2026-05-18T02:00:29Z"},{"alias_kind":"pith_short_12","alias_value":"533YWCXDR2ZP","created_at":"2026-05-18T12:26:20Z"},{"alias_kind":"pith_short_16","alias_value":"533YWCXDR2ZPOONB","created_at":"2026-05-18T12:26:20Z"},{"alias_kind":"pith_short_8","alias_value":"533YWCXD","created_at":"2026-05-18T12:26:20Z"}],"graph_snapshots":[{"event_id":"sha256:0e2ebd76cdf386bdcf617eea327eb64e338a374405f9d18b3323fa2d0ccea6f9","target":"graph","created_at":"2026-05-18T02:00:29Z","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 present TreeCol, a new and efficient tree-based scheme to calculate column densities in numerical simulations. Knowing the column density in any direction at any location in space is a prerequisite for modelling the propagation of radiation through the computational domain. TreeCol therefore forms the basis for a fast, approximate method for modelling the attenuation of radiation within large numerical simulations. It constructs a HEALPix sphere at any desired location and accumulates the column density by walking the tree and by adding up the contributions from all tree nodes whose line of","authors_text":"Paul C. Clark, Ralf S. Klessen, Simon C.O. Glover","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-09-18T11:40:13Z","title":"TreeCol: a novel approach to estimating column densities in astrophysical simulations"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1109.3861","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":"sha256:8cb551d6d206d8bd2da598874c296bd51bc5c4d5bd424717cc105f0774303b75","target":"record","created_at":"2026-05-18T02:00:29Z","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":"6cd75edecc52fbc50add4719e2aa4f4a9c70d813ee31fd0e0753bf8caae7a015","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-09-18T11:40:13Z","title_canon_sha256":"cea025a39c2bc445fd39fd67887b518560dfa95d260bad40e7c9b142bdffd9d9"},"schema_version":"1.0","source":{"id":"1109.3861","kind":"arxiv","version":1}},"canonical_sha256":"eef78b0ae38eb2f739a15286995db9477ae8205c57f2d066c1af05352ef5ae51","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"eef78b0ae38eb2f739a15286995db9477ae8205c57f2d066c1af05352ef5ae51","first_computed_at":"2026-05-18T02:00:29.655106Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:00:29.655106Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"cqA+deAeDOhh9sY+7waxBroLTvt6qsRL+nkyVT6qOdhZuBUzL6Qj126IEfOhJutXkLKl2DzxCWBAdiB+ZKZ8DA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:00:29.655604Z","signed_message":"canonical_sha256_bytes"},"source_id":"1109.3861","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:8cb551d6d206d8bd2da598874c296bd51bc5c4d5bd424717cc105f0774303b75","sha256:0e2ebd76cdf386bdcf617eea327eb64e338a374405f9d18b3323fa2d0ccea6f9"],"state_sha256":"7b0455e51320d141506b007ed8d3c9a7b4bf179f7c7823af91a7185d6f63c380"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"3dKUrzdC28Ao/JcPPbtywcGyvmccGnz0Aid9lpKz6Ax3oPSHk1x/B+L1N3EcjL55Rj+28XQ58K/G42pHIi7sBA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-06T21:19:26.325389Z","bundle_sha256":"c792e0079070ad693bca77fd2001c3ff788363a647413ba8343afd2cf52ff03e"}}