{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2005:PGID2ZKUYFAPPXB6WIZY37QZEG","short_pith_number":"pith:PGID2ZKU","canonical_record":{"source":{"id":"astro-ph/0510040","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2005-10-03T12:26:05Z","cross_cats_sorted":[],"title_canon_sha256":"6bf145b95e18d54d46318a43a1eedde41ea2f15c7db93d3fbbc98257c56f6c29","abstract_canon_sha256":"47a6d1f306293f06095386844140616d6f244308738b157eddf3dfbea600bdf3"},"schema_version":"1.0"},"canonical_sha256":"79903d6554c140f7dc3eb2338dfe19218973af15e0a7571e777d4d107a1bf54c","source":{"kind":"arxiv","id":"astro-ph/0510040","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0510040","created_at":"2026-05-18T01:07:26Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0510040v1","created_at":"2026-05-18T01:07:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0510040","created_at":"2026-05-18T01:07:26Z"},{"alias_kind":"pith_short_12","alias_value":"PGID2ZKUYFAP","created_at":"2026-05-18T12:25:53Z"},{"alias_kind":"pith_short_16","alias_value":"PGID2ZKUYFAPPXB6","created_at":"2026-05-18T12:25:53Z"},{"alias_kind":"pith_short_8","alias_value":"PGID2ZKU","created_at":"2026-05-18T12:25:53Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2005:PGID2ZKUYFAPPXB6WIZY37QZEG","target":"record","payload":{"canonical_record":{"source":{"id":"astro-ph/0510040","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"astro-ph","submitted_at":"2005-10-03T12:26:05Z","cross_cats_sorted":[],"title_canon_sha256":"6bf145b95e18d54d46318a43a1eedde41ea2f15c7db93d3fbbc98257c56f6c29","abstract_canon_sha256":"47a6d1f306293f06095386844140616d6f244308738b157eddf3dfbea600bdf3"},"schema_version":"1.0"},"canonical_sha256":"79903d6554c140f7dc3eb2338dfe19218973af15e0a7571e777d4d107a1bf54c","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:07:26.268362Z","signature_b64":"xXstMKMzP4o0QBDWchJVAwLfYqb9YhsNUAE48egLEYghWXLboy7T0YDzIR2X5yuuqK4mFsBzcPFhWSl1eqPaAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"79903d6554c140f7dc3eb2338dfe19218973af15e0a7571e777d4d107a1bf54c","last_reissued_at":"2026-05-18T01:07:26.267540Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:07:26.267540Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"astro-ph/0510040","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":"2026-05-18T01:07:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"oNjrLnGgRr4Ym6/LGk+QEeI54oCL2UXfO6PkkjJLrUvv6Ns/nynTjQ2G1RUyq2bJRt0drMlW+vc9s5X0nnSwBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T09:24:45.259212Z"},"content_sha256":"0442deb889f9c0357c4debe5e592a3cb32f17758938f3d357f83019eebba31ed","schema_version":"1.0","event_id":"sha256:0442deb889f9c0357c4debe5e592a3cb32f17758938f3d357f83019eebba31ed"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2005:PGID2ZKUYFAPPXB6WIZY37QZEG","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"XMM-Newton view of PKS 2155-304: hardness ratio and cross-correlation analysis of EPIC pn observations","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"A. Treves (Insubria University), F.K. Liu (PKU), J.M. Bai (Yunnan Observatory), L. Maraschi (OAB), Y.H. Zhang (Tsinghua University)","submitted_at":"2005-10-03T12:26:05Z","abstract_excerpt":"With currently available XMM-Newton EPIC pn observations spanned over about 3 years, we present a detailed spectral and temporal variability of the 0.2--10 keV X-ray emission from the X-ray bright BL Lac object PKS 2155-304. The spectral variability is examined with a model independent hardness ratio method. We find that the spectral evolution of the source follows the light curves well, indicating that the spectra harden when the fluxes increase. The plots of hardness ratios versus count rates show that the spectral changes are particularly significant during flares. The cross-correlation fun"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0510040","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":"2026-05-18T01:07:26Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"O5QIE80jrWoHr6HuvvnQWLJmtM+11FQJWgHW9LvX9scBkOmJc1FJpKtnIi+Y44woNGy6ucbaCxIrmmTsGCDWAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T09:24:45.259563Z"},"content_sha256":"0f8b1ec6668f41f2abf813e53255d4cecd8db93b3055cc0fa840eda706a7141d","schema_version":"1.0","event_id":"sha256:0f8b1ec6668f41f2abf813e53255d4cecd8db93b3055cc0fa840eda706a7141d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/PGID2ZKUYFAPPXB6WIZY37QZEG/bundle.json","state_url":"https://pith.science/pith/PGID2ZKUYFAPPXB6WIZY37QZEG/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/PGID2ZKUYFAPPXB6WIZY37QZEG/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":"2026-06-27T09:24:45Z","links":{"resolver":"https://pith.science/pith/PGID2ZKUYFAPPXB6WIZY37QZEG","bundle":"https://pith.science/pith/PGID2ZKUYFAPPXB6WIZY37QZEG/bundle.json","state":"https://pith.science/pith/PGID2ZKUYFAPPXB6WIZY37QZEG/state.json","well_known_bundle":"https://pith.science/.well-known/pith/PGID2ZKUYFAPPXB6WIZY37QZEG/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2005:PGID2ZKUYFAPPXB6WIZY37QZEG","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":"47a6d1f306293f06095386844140616d6f244308738b157eddf3dfbea600bdf3","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2005-10-03T12:26:05Z","title_canon_sha256":"6bf145b95e18d54d46318a43a1eedde41ea2f15c7db93d3fbbc98257c56f6c29"},"schema_version":"1.0","source":{"id":"astro-ph/0510040","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"astro-ph/0510040","created_at":"2026-05-18T01:07:26Z"},{"alias_kind":"arxiv_version","alias_value":"astro-ph/0510040v1","created_at":"2026-05-18T01:07:26Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.astro-ph/0510040","created_at":"2026-05-18T01:07:26Z"},{"alias_kind":"pith_short_12","alias_value":"PGID2ZKUYFAP","created_at":"2026-05-18T12:25:53Z"},{"alias_kind":"pith_short_16","alias_value":"PGID2ZKUYFAPPXB6","created_at":"2026-05-18T12:25:53Z"},{"alias_kind":"pith_short_8","alias_value":"PGID2ZKU","created_at":"2026-05-18T12:25:53Z"}],"graph_snapshots":[{"event_id":"sha256:0f8b1ec6668f41f2abf813e53255d4cecd8db93b3055cc0fa840eda706a7141d","target":"graph","created_at":"2026-05-18T01:07:26Z","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":"With currently available XMM-Newton EPIC pn observations spanned over about 3 years, we present a detailed spectral and temporal variability of the 0.2--10 keV X-ray emission from the X-ray bright BL Lac object PKS 2155-304. The spectral variability is examined with a model independent hardness ratio method. We find that the spectral evolution of the source follows the light curves well, indicating that the spectra harden when the fluxes increase. The plots of hardness ratios versus count rates show that the spectral changes are particularly significant during flares. The cross-correlation fun","authors_text":"A. Treves (Insubria University), F.K. Liu (PKU), J.M. Bai (Yunnan Observatory), L. Maraschi (OAB), Y.H. Zhang (Tsinghua University)","cross_cats":[],"headline":"","license":"","primary_cat":"astro-ph","submitted_at":"2005-10-03T12:26:05Z","title":"XMM-Newton view of PKS 2155-304: hardness ratio and cross-correlation analysis of EPIC pn observations"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0510040","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":"sha256:0442deb889f9c0357c4debe5e592a3cb32f17758938f3d357f83019eebba31ed","target":"record","created_at":"2026-05-18T01:07:26Z","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":"47a6d1f306293f06095386844140616d6f244308738b157eddf3dfbea600bdf3","cross_cats_sorted":[],"license":"","primary_cat":"astro-ph","submitted_at":"2005-10-03T12:26:05Z","title_canon_sha256":"6bf145b95e18d54d46318a43a1eedde41ea2f15c7db93d3fbbc98257c56f6c29"},"schema_version":"1.0","source":{"id":"astro-ph/0510040","kind":"arxiv","version":1}},"canonical_sha256":"79903d6554c140f7dc3eb2338dfe19218973af15e0a7571e777d4d107a1bf54c","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"79903d6554c140f7dc3eb2338dfe19218973af15e0a7571e777d4d107a1bf54c","first_computed_at":"2026-05-18T01:07:26.267540Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:07:26.267540Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"xXstMKMzP4o0QBDWchJVAwLfYqb9YhsNUAE48egLEYghWXLboy7T0YDzIR2X5yuuqK4mFsBzcPFhWSl1eqPaAw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:07:26.268362Z","signed_message":"canonical_sha256_bytes"},"source_id":"astro-ph/0510040","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0442deb889f9c0357c4debe5e592a3cb32f17758938f3d357f83019eebba31ed","sha256:0f8b1ec6668f41f2abf813e53255d4cecd8db93b3055cc0fa840eda706a7141d"],"state_sha256":"8a95ce146654807c354c20ec5d4b2328046dd500b013f4d4231767d2dbebfd2c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"t62xoDoOcHYmK9/Chk/kqajN3FdncKoBqCG00LRyX55JXDDKe4HneRH9qBUyj3qKNbuFTR/r0/7HjyEnZ+7+BA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-27T09:24:45.261389Z","bundle_sha256":"d81adbbdd1223c720d5211db48385d5dcc164f29384c484f4b1ca2395853285e"}}