{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2023:A4T6H7HP3D6EWY4YQO2GAZWSOH","short_pith_number":"pith:A4T6H7HP","canonical_record":{"source":{"id":"2307.15831","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2023-07-28T22:36:57Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"b8bb42496029d7f2f7e7885df47abfe342e7f3718fe02d76fbfdca1a891370d7","abstract_canon_sha256":"19b5efee37804431827a99f6ebfa7f6e29dd654c0cba5df58731c0cd19141cb3"},"schema_version":"1.0"},"canonical_sha256":"0727e3fcefd8fc4b639883b46066d271c6afe310bc51d04dd72d4b0b1264ed3e","source":{"kind":"arxiv","id":"2307.15831","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2307.15831","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"arxiv_version","alias_value":"2307.15831v1","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2307.15831","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"pith_short_12","alias_value":"A4T6H7HP3D6E","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"pith_short_16","alias_value":"A4T6H7HP3D6EWY4Y","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"pith_short_8","alias_value":"A4T6H7HP","created_at":"2026-07-05T06:35:54Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2023:A4T6H7HP3D6EWY4YQO2GAZWSOH","target":"record","payload":{"canonical_record":{"source":{"id":"2307.15831","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2023-07-28T22:36:57Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"b8bb42496029d7f2f7e7885df47abfe342e7f3718fe02d76fbfdca1a891370d7","abstract_canon_sha256":"19b5efee37804431827a99f6ebfa7f6e29dd654c0cba5df58731c0cd19141cb3"},"schema_version":"1.0"},"canonical_sha256":"0727e3fcefd8fc4b639883b46066d271c6afe310bc51d04dd72d4b0b1264ed3e","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T06:35:54.997940Z","signature_b64":"Bs5QspdGnJVw1q+mQyn2q6Dhq4qECeb2yIbYcCvuo3xWnHCYvihOXbddNXUDeMrioVSyBZKsQk5ipfPNz8lfCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0727e3fcefd8fc4b639883b46066d271c6afe310bc51d04dd72d4b0b1264ed3e","last_reissued_at":"2026-07-05T06:35:54.997465Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T06:35:54.997465Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2307.15831","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":"2026-07-05T06:35:54Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"LbVPtTTewCFdyP9KScMufcQon1Ws9iGpm+KegxKFoWF/DTTRSMsSBXepttozywEyCgpaCTvT4fE16JOazffMCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-11T16:44:12.749561Z"},"content_sha256":"fe7c62b18a705099f75a268315980a1ff23e68c200f373d40ffbb273e4415e9d","schema_version":"1.0","event_id":"sha256:fe7c62b18a705099f75a268315980a1ff23e68c200f373d40ffbb273e4415e9d"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2023:A4T6H7HP3D6EWY4YQO2GAZWSOH","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Universal Upper End of the Stellar Initial Mass Function in the Young and Compact LEGUS clusters","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.GA","authors_text":"Aaron S. Evans, Aida Wofford, Angela Adamo, Bruce G. Elmegreen, Clare L. Dobbs, Daniela Calzetti, Daniel Schaerer, David O. Cook, Deidre A. Hunter, Dooseok Escher Jung, Elena Sabbi, John S. Gallagher III, Kelsey E. Johnson, Linda J. Smith, Mark Heyer, Mark R. Krumholz, Matteo Messa, Mattia Sirressi, Michele Cignoni, Michele Fumagalli, Monica Tosi, Robert C. Kennicutt Jr., Rupali Chandar, Sean T. Linden","submitted_at":"2023-07-28T22:36:57Z","abstract_excerpt":"We investigate the variation in the upper end of stellar initial mass function (uIMF) in 375 young and compact star clusters in five nearby galaxies within $\\sim 5$ Mpc. All the young stellar clusters (YSCs) in the sample have ages $\\lesssim 4$ Myr and masses above 500 $M_{\\odot}$, according to standard stellar models. The YSC catalogs were produced from Hubble Space Telescope images obtained as part of the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. They are used here to test whether the uIMF is universal or changes as a function of the cluster's stellar mass. We perform t"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2307.15831","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2307.15831/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":"2026-07-05T06:35:54Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"xjixz6n1hIyfc9gBxpDyDQRY313Z6p2mmlbdYXg99flueptLMw3llCiwgmpp26XObILGcSeQjUZKFcrGIp0DCA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-11T16:44:12.749945Z"},"content_sha256":"4b77cb9fdac92d85cfc094860f330f27a4cd82dc98071a8c00b06408f8de1bce","schema_version":"1.0","event_id":"sha256:4b77cb9fdac92d85cfc094860f330f27a4cd82dc98071a8c00b06408f8de1bce"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH/bundle.json","state_url":"https://pith.science/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH/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":"2026-07-11T16:44:12Z","links":{"resolver":"https://pith.science/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH","bundle":"https://pith.science/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH/bundle.json","state":"https://pith.science/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH/state.json","well_known_bundle":"https://pith.science/.well-known/pith/A4T6H7HP3D6EWY4YQO2GAZWSOH/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2023:A4T6H7HP3D6EWY4YQO2GAZWSOH","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":"19b5efee37804431827a99f6ebfa7f6e29dd654c0cba5df58731c0cd19141cb3","cross_cats_sorted":["astro-ph.SR"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2023-07-28T22:36:57Z","title_canon_sha256":"b8bb42496029d7f2f7e7885df47abfe342e7f3718fe02d76fbfdca1a891370d7"},"schema_version":"1.0","source":{"id":"2307.15831","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2307.15831","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"arxiv_version","alias_value":"2307.15831v1","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2307.15831","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"pith_short_12","alias_value":"A4T6H7HP3D6E","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"pith_short_16","alias_value":"A4T6H7HP3D6EWY4Y","created_at":"2026-07-05T06:35:54Z"},{"alias_kind":"pith_short_8","alias_value":"A4T6H7HP","created_at":"2026-07-05T06:35:54Z"}],"graph_snapshots":[{"event_id":"sha256:4b77cb9fdac92d85cfc094860f330f27a4cd82dc98071a8c00b06408f8de1bce","target":"graph","created_at":"2026-07-05T06:35:54Z","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/2307.15831/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We investigate the variation in the upper end of stellar initial mass function (uIMF) in 375 young and compact star clusters in five nearby galaxies within $\\sim 5$ Mpc. All the young stellar clusters (YSCs) in the sample have ages $\\lesssim 4$ Myr and masses above 500 $M_{\\odot}$, according to standard stellar models. The YSC catalogs were produced from Hubble Space Telescope images obtained as part of the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. They are used here to test whether the uIMF is universal or changes as a function of the cluster's stellar mass. We perform t","authors_text":"Aaron S. Evans, Aida Wofford, Angela Adamo, Bruce G. Elmegreen, Clare L. Dobbs, Daniela Calzetti, Daniel Schaerer, David O. Cook, Deidre A. Hunter, Dooseok Escher Jung, Elena Sabbi, John S. Gallagher III, Kelsey E. Johnson, Linda J. Smith, Mark Heyer, Mark R. Krumholz, Matteo Messa, Mattia Sirressi, Michele Cignoni, Michele Fumagalli, Monica Tosi, Robert C. Kennicutt Jr., Rupali Chandar, Sean T. Linden","cross_cats":["astro-ph.SR"],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2023-07-28T22:36:57Z","title":"Universal Upper End of the Stellar Initial Mass Function in the Young and Compact LEGUS clusters"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2307.15831","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:fe7c62b18a705099f75a268315980a1ff23e68c200f373d40ffbb273e4415e9d","target":"record","created_at":"2026-07-05T06:35:54Z","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":"19b5efee37804431827a99f6ebfa7f6e29dd654c0cba5df58731c0cd19141cb3","cross_cats_sorted":["astro-ph.SR"],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"astro-ph.GA","submitted_at":"2023-07-28T22:36:57Z","title_canon_sha256":"b8bb42496029d7f2f7e7885df47abfe342e7f3718fe02d76fbfdca1a891370d7"},"schema_version":"1.0","source":{"id":"2307.15831","kind":"arxiv","version":1}},"canonical_sha256":"0727e3fcefd8fc4b639883b46066d271c6afe310bc51d04dd72d4b0b1264ed3e","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0727e3fcefd8fc4b639883b46066d271c6afe310bc51d04dd72d4b0b1264ed3e","first_computed_at":"2026-07-05T06:35:54.997465Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T06:35:54.997465Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Bs5QspdGnJVw1q+mQyn2q6Dhq4qECeb2yIbYcCvuo3xWnHCYvihOXbddNXUDeMrioVSyBZKsQk5ipfPNz8lfCQ==","signature_status":"signed_v1","signed_at":"2026-07-05T06:35:54.997940Z","signed_message":"canonical_sha256_bytes"},"source_id":"2307.15831","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:fe7c62b18a705099f75a268315980a1ff23e68c200f373d40ffbb273e4415e9d","sha256:4b77cb9fdac92d85cfc094860f330f27a4cd82dc98071a8c00b06408f8de1bce"],"state_sha256":"d2de68d21d63f2dd7104e993f9d7f77777899a338b110ca8a785ffa847325e1c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QQWxU++a0/YRV9I64wv7FdVfDLKTUl+fFo2oNcHKKS1xctzol9Rg7058+BnTD4qgod+tHN3L8i5cCanwkLVXBQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-11T16:44:12.755060Z","bundle_sha256":"9f3baec6db5171759f8301fce16557cb436ce6b40e9ab78de54c4f60e1b05ae3"}}