{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2012:QGAGCYN2DZY4F4LKBLJKWQKXFL","short_pith_number":"pith:QGAGCYN2","canonical_record":{"source":{"id":"1212.5866","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-12-24T06:30:14Z","cross_cats_sorted":["astro-ph.CO","hep-ph"],"title_canon_sha256":"5e661ae166dba8397d6f1a78b96edcf59e621dd6c136f15011abc88269bff032","abstract_canon_sha256":"e3c9a5caa5e0d6b054678734299b8e51a783548a418c006b2ab8586d465247c5"},"schema_version":"1.0"},"canonical_sha256":"81806161ba1e71c2f16a0ad2ab41572af89ba9a49df030f54f6091509ed6b49d","source":{"kind":"arxiv","id":"1212.5866","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1212.5866","created_at":"2026-05-18T03:37:51Z"},{"alias_kind":"arxiv_version","alias_value":"1212.5866v1","created_at":"2026-05-18T03:37:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1212.5866","created_at":"2026-05-18T03:37:51Z"},{"alias_kind":"pith_short_12","alias_value":"QGAGCYN2DZY4","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_16","alias_value":"QGAGCYN2DZY4F4LK","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_8","alias_value":"QGAGCYN2","created_at":"2026-05-18T12:27:18Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2012:QGAGCYN2DZY4F4LKBLJKWQKXFL","target":"record","payload":{"canonical_record":{"source":{"id":"1212.5866","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-12-24T06:30:14Z","cross_cats_sorted":["astro-ph.CO","hep-ph"],"title_canon_sha256":"5e661ae166dba8397d6f1a78b96edcf59e621dd6c136f15011abc88269bff032","abstract_canon_sha256":"e3c9a5caa5e0d6b054678734299b8e51a783548a418c006b2ab8586d465247c5"},"schema_version":"1.0"},"canonical_sha256":"81806161ba1e71c2f16a0ad2ab41572af89ba9a49df030f54f6091509ed6b49d","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:37:51.153217Z","signature_b64":"8NV6N311oCfPnhHpliR5K6GwU833IQVAZPn6E5Ll9c5lsWw069m8obXE0BB9TuijOjy7HIm9S33k51E0EzJvBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"81806161ba1e71c2f16a0ad2ab41572af89ba9a49df030f54f6091509ed6b49d","last_reissued_at":"2026-05-18T03:37:51.152251Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:37:51.152251Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1212.5866","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":"2026-05-18T03:37:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"75xhe6kxxZ5mG2vjft2dqU5jIHv0gezvLsSvoX4fCU8Xqgnbi3+cxv1P9nI2f0LA6rPD7CNK6A/vCsa0gUR+CQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T08:57:14.546522Z"},"content_sha256":"354f09d0199c3c5ddc486b7d9f94d52d5f5f38adf7d6ec5db9e3481e089bb3b3","schema_version":"1.0","event_id":"sha256:354f09d0199c3c5ddc486b7d9f94d52d5f5f38adf7d6ec5db9e3481e089bb3b3"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2012:QGAGCYN2DZY4F4LKBLJKWQKXFL","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Measuring the extragalactic background light from very high energy gamma-ray observations of blazars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","hep-ph"],"primary_cat":"astro-ph.HE","authors_text":"Hai-Liang Huang (IHEP, Hong-Hao Zhang (SYSU), Qiang Yuan (IHEP), SYSU), Xiao-Jun Bi (IHEP)","submitted_at":"2012-12-24T06:30:14Z","abstract_excerpt":"The extragalactic background light (EBL) contains important information about stellar and galaxy evolution. It leaves imprint on the very high energy $\\gamma$-ray spectra from sources at cosmological distances due to the process of pair production. In this work we propose to {\\em measure} the EBL directly by extracting the collective attenuation effects in a number of $\\gamma$-ray sources at different redshifts. Using a Markov Chain Monte Carlo fitting method, the EBL intensities and the intrinsic spectral parameters of $\\gamma$-ray sources are derived simultaneously. No prior shape of EBL is "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1212.5866","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":"2026-05-18T03:37:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"TX4xmA3RPq+GvTDPXi5NnKAdHMS2LGLRIs5bd0cTe0Ss+bc2X/tlH1cOJVblyEFYzS+1srVD/DmiyyVLJfUIBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-31T08:57:14.547254Z"},"content_sha256":"96d89835a73e90997b1910a6c5e956930505177697bba8808350ba8a9019dc6f","schema_version":"1.0","event_id":"sha256:96d89835a73e90997b1910a6c5e956930505177697bba8808350ba8a9019dc6f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL/bundle.json","state_url":"https://pith.science/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL/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":"2026-05-31T08:57:14Z","links":{"resolver":"https://pith.science/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL","bundle":"https://pith.science/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL/bundle.json","state":"https://pith.science/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QGAGCYN2DZY4F4LKBLJKWQKXFL/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2012:QGAGCYN2DZY4F4LKBLJKWQKXFL","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":"e3c9a5caa5e0d6b054678734299b8e51a783548a418c006b2ab8586d465247c5","cross_cats_sorted":["astro-ph.CO","hep-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-12-24T06:30:14Z","title_canon_sha256":"5e661ae166dba8397d6f1a78b96edcf59e621dd6c136f15011abc88269bff032"},"schema_version":"1.0","source":{"id":"1212.5866","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1212.5866","created_at":"2026-05-18T03:37:51Z"},{"alias_kind":"arxiv_version","alias_value":"1212.5866v1","created_at":"2026-05-18T03:37:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1212.5866","created_at":"2026-05-18T03:37:51Z"},{"alias_kind":"pith_short_12","alias_value":"QGAGCYN2DZY4","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_16","alias_value":"QGAGCYN2DZY4F4LK","created_at":"2026-05-18T12:27:18Z"},{"alias_kind":"pith_short_8","alias_value":"QGAGCYN2","created_at":"2026-05-18T12:27:18Z"}],"graph_snapshots":[{"event_id":"sha256:96d89835a73e90997b1910a6c5e956930505177697bba8808350ba8a9019dc6f","target":"graph","created_at":"2026-05-18T03:37:51Z","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":"The extragalactic background light (EBL) contains important information about stellar and galaxy evolution. It leaves imprint on the very high energy $\\gamma$-ray spectra from sources at cosmological distances due to the process of pair production. In this work we propose to {\\em measure} the EBL directly by extracting the collective attenuation effects in a number of $\\gamma$-ray sources at different redshifts. Using a Markov Chain Monte Carlo fitting method, the EBL intensities and the intrinsic spectral parameters of $\\gamma$-ray sources are derived simultaneously. No prior shape of EBL is ","authors_text":"Hai-Liang Huang (IHEP, Hong-Hao Zhang (SYSU), Qiang Yuan (IHEP), SYSU), Xiao-Jun Bi (IHEP)","cross_cats":["astro-ph.CO","hep-ph"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-12-24T06:30:14Z","title":"Measuring the extragalactic background light from very high energy gamma-ray observations of blazars"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1212.5866","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":"sha256:354f09d0199c3c5ddc486b7d9f94d52d5f5f38adf7d6ec5db9e3481e089bb3b3","target":"record","created_at":"2026-05-18T03:37:51Z","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":"e3c9a5caa5e0d6b054678734299b8e51a783548a418c006b2ab8586d465247c5","cross_cats_sorted":["astro-ph.CO","hep-ph"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2012-12-24T06:30:14Z","title_canon_sha256":"5e661ae166dba8397d6f1a78b96edcf59e621dd6c136f15011abc88269bff032"},"schema_version":"1.0","source":{"id":"1212.5866","kind":"arxiv","version":1}},"canonical_sha256":"81806161ba1e71c2f16a0ad2ab41572af89ba9a49df030f54f6091509ed6b49d","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"81806161ba1e71c2f16a0ad2ab41572af89ba9a49df030f54f6091509ed6b49d","first_computed_at":"2026-05-18T03:37:51.152251Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:37:51.152251Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"8NV6N311oCfPnhHpliR5K6GwU833IQVAZPn6E5Ll9c5lsWw069m8obXE0BB9TuijOjy7HIm9S33k51E0EzJvBQ==","signature_status":"signed_v1","signed_at":"2026-05-18T03:37:51.153217Z","signed_message":"canonical_sha256_bytes"},"source_id":"1212.5866","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:354f09d0199c3c5ddc486b7d9f94d52d5f5f38adf7d6ec5db9e3481e089bb3b3","sha256:96d89835a73e90997b1910a6c5e956930505177697bba8808350ba8a9019dc6f"],"state_sha256":"594ef9bc4c9b8b618b05a1b94f30b96b962a818470017fe51ad81c44f17c3e18"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"l161sCY5IGZjsWnhIvZg8+9JPHd+SCCXN89WkL+zlqfbyS/2x4X9IATzXGJJY3WoR9uqWhFoblHZAjJ2h1FbAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-31T08:57:14.551937Z","bundle_sha256":"921f7e83a89576e2751206abc45b79b735765daf1a997a4549327b4b9455937c"}}