{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2008:EUNKD2ZEIZFEVVU4LN6X4QXDTY","short_pith_number":"pith:EUNKD2ZE","canonical_record":{"source":{"id":"0806.3752","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-06-23T20:04:11Z","cross_cats_sorted":[],"title_canon_sha256":"23ba50d2083f9f672b91520ad27fd8f195736dd8eafe3a5dbb94013b3aad1a1c","abstract_canon_sha256":"8a2ee97a9bb6daea79396ad21c9bfbd7da8e3681d382d6da8f70eb0da7b4d3d0"},"schema_version":"1.0"},"canonical_sha256":"251aa1eb24464a4ad69c5b7d7e42e39e15218f84bc7bcac91c45127287b7facf","source":{"kind":"arxiv","id":"0806.3752","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0806.3752","created_at":"2026-05-18T03:54:39Z"},{"alias_kind":"arxiv_version","alias_value":"0806.3752v2","created_at":"2026-05-18T03:54:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0806.3752","created_at":"2026-05-18T03:54:39Z"},{"alias_kind":"pith_short_12","alias_value":"EUNKD2ZEIZFE","created_at":"2026-05-18T12:25:57Z"},{"alias_kind":"pith_short_16","alias_value":"EUNKD2ZEIZFEVVU4","created_at":"2026-05-18T12:25:57Z"},{"alias_kind":"pith_short_8","alias_value":"EUNKD2ZE","created_at":"2026-05-18T12:25:57Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2008:EUNKD2ZEIZFEVVU4LN6X4QXDTY","target":"record","payload":{"canonical_record":{"source":{"id":"0806.3752","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-06-23T20:04:11Z","cross_cats_sorted":[],"title_canon_sha256":"23ba50d2083f9f672b91520ad27fd8f195736dd8eafe3a5dbb94013b3aad1a1c","abstract_canon_sha256":"8a2ee97a9bb6daea79396ad21c9bfbd7da8e3681d382d6da8f70eb0da7b4d3d0"},"schema_version":"1.0"},"canonical_sha256":"251aa1eb24464a4ad69c5b7d7e42e39e15218f84bc7bcac91c45127287b7facf","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:54:39.729443Z","signature_b64":"+aHzXZ5j0/eJKrN0/sjP8gGbCYZuWUaPFsIjaZ8Ansd0R2FN9TCgcXbmaEJ3m9wdKxF/WdOlCgj58J3zP/O2Cg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"251aa1eb24464a4ad69c5b7d7e42e39e15218f84bc7bcac91c45127287b7facf","last_reissued_at":"2026-05-18T03:54:39.728752Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:54:39.728752Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0806.3752","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":"2026-05-18T03:54:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"z3Yt35IE4Hd0yRaTgK6NciH1v++7mPlIcWf4P6niU5bwPNM/I5v4uNE28Mv13H3YkzGxFye4m32CvKAGPmJ+Dg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T20:48:09.971077Z"},"content_sha256":"5b65b32000b58b2cea18c856985a0151a8b7c63c1e6a04fc6302c207f6577381","schema_version":"1.0","event_id":"sha256:5b65b32000b58b2cea18c856985a0151a8b7c63c1e6a04fc6302c207f6577381"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2008:EUNKD2ZEIZFEVVU4LN6X4QXDTY","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"ACS imaging of star clusters in M51 II. The luminosity function and mass function across the disk","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"H.J.G.L.M. Lamers, M. Gieles, M.R. Haas, R.A. Scheepmaker, S.S. Larsen","submitted_at":"2008-06-23T20:04:11Z","abstract_excerpt":"Whether or not there exists a physical upper mass limit for star clusters is still unclear. HST/ACS data for the rich cluster population in the interacting galaxy M51 enables us to investigate this in more detail. We investigate whether the cluster luminosity function (LF) in M51 shows evidence for an upper limit to the mass function. The variations of the LF parameters with position on the disk are addressed. We determine the cluster LF for all clusters in M51 falling within our selection criteria, as well as for several subsets of the sample. In that way we can determine the properties of th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0806.3752","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":""},"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":"2026-05-18T03:54:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rAN5S/mFVu4cgUBjNY6nZCfP5jOMkBtQYHmsYqRyDkgUui/Xsn8/oWrPWrHuDEmvuivKNFaP3hUuco4tzubKBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T20:48:09.971797Z"},"content_sha256":"8cb009eaf5760106c9eec8f7c3581b136c254de7ceabb31e830da09247068a13","schema_version":"1.0","event_id":"sha256:8cb009eaf5760106c9eec8f7c3581b136c254de7ceabb31e830da09247068a13"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY/bundle.json","state_url":"https://pith.science/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY/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":"2026-05-25T20:48:09Z","links":{"resolver":"https://pith.science/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY","bundle":"https://pith.science/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY/bundle.json","state":"https://pith.science/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EUNKD2ZEIZFEVVU4LN6X4QXDTY/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2008:EUNKD2ZEIZFEVVU4LN6X4QXDTY","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":"8a2ee97a9bb6daea79396ad21c9bfbd7da8e3681d382d6da8f70eb0da7b4d3d0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-06-23T20:04:11Z","title_canon_sha256":"23ba50d2083f9f672b91520ad27fd8f195736dd8eafe3a5dbb94013b3aad1a1c"},"schema_version":"1.0","source":{"id":"0806.3752","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0806.3752","created_at":"2026-05-18T03:54:39Z"},{"alias_kind":"arxiv_version","alias_value":"0806.3752v2","created_at":"2026-05-18T03:54:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0806.3752","created_at":"2026-05-18T03:54:39Z"},{"alias_kind":"pith_short_12","alias_value":"EUNKD2ZEIZFE","created_at":"2026-05-18T12:25:57Z"},{"alias_kind":"pith_short_16","alias_value":"EUNKD2ZEIZFEVVU4","created_at":"2026-05-18T12:25:57Z"},{"alias_kind":"pith_short_8","alias_value":"EUNKD2ZE","created_at":"2026-05-18T12:25:57Z"}],"graph_snapshots":[{"event_id":"sha256:8cb009eaf5760106c9eec8f7c3581b136c254de7ceabb31e830da09247068a13","target":"graph","created_at":"2026-05-18T03:54:39Z","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":"Whether or not there exists a physical upper mass limit for star clusters is still unclear. HST/ACS data for the rich cluster population in the interacting galaxy M51 enables us to investigate this in more detail. We investigate whether the cluster luminosity function (LF) in M51 shows evidence for an upper limit to the mass function. The variations of the LF parameters with position on the disk are addressed. We determine the cluster LF for all clusters in M51 falling within our selection criteria, as well as for several subsets of the sample. In that way we can determine the properties of th","authors_text":"H.J.G.L.M. Lamers, M. Gieles, M.R. Haas, R.A. Scheepmaker, S.S. Larsen","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-06-23T20:04:11Z","title":"ACS imaging of star clusters in M51 II. The luminosity function and mass function across the disk"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0806.3752","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":"sha256:5b65b32000b58b2cea18c856985a0151a8b7c63c1e6a04fc6302c207f6577381","target":"record","created_at":"2026-05-18T03:54:39Z","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":"8a2ee97a9bb6daea79396ad21c9bfbd7da8e3681d382d6da8f70eb0da7b4d3d0","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph","submitted_at":"2008-06-23T20:04:11Z","title_canon_sha256":"23ba50d2083f9f672b91520ad27fd8f195736dd8eafe3a5dbb94013b3aad1a1c"},"schema_version":"1.0","source":{"id":"0806.3752","kind":"arxiv","version":2}},"canonical_sha256":"251aa1eb24464a4ad69c5b7d7e42e39e15218f84bc7bcac91c45127287b7facf","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"251aa1eb24464a4ad69c5b7d7e42e39e15218f84bc7bcac91c45127287b7facf","first_computed_at":"2026-05-18T03:54:39.728752Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:54:39.728752Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"+aHzXZ5j0/eJKrN0/sjP8gGbCYZuWUaPFsIjaZ8Ansd0R2FN9TCgcXbmaEJ3m9wdKxF/WdOlCgj58J3zP/O2Cg==","signature_status":"signed_v1","signed_at":"2026-05-18T03:54:39.729443Z","signed_message":"canonical_sha256_bytes"},"source_id":"0806.3752","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:5b65b32000b58b2cea18c856985a0151a8b7c63c1e6a04fc6302c207f6577381","sha256:8cb009eaf5760106c9eec8f7c3581b136c254de7ceabb31e830da09247068a13"],"state_sha256":"984fa9b25a119f8186681d0efc045cbd2c91dc1bc3efcae3c32e33c0e615fd49"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"twNWc6LgvE/3QhyZYDOtia1UpFe5Dk/VhKhG6KkEC+bMh1+tScwXjWHH7NxszCVr1Ih5Zesn5f4ZjNsS8iwyCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T20:48:09.975556Z","bundle_sha256":"6e3a03a25d06ac0933f84523865c712cb7eb0a6d0415428b8ebd7d6445e91ddb"}}