{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2011:UKNDBB2J743UQN4XXFXXXA2JCP","short_pith_number":"pith:UKNDBB2J","canonical_record":{"source":{"id":"1112.4349","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-12-19T14:35:19Z","cross_cats_sorted":[],"title_canon_sha256":"0e7dbca621ffd00a88a1fd57793dacda21a46891123a085042c67a0314b55701","abstract_canon_sha256":"58934c6b5417732a04af2f3cb2426943d0c013ad1464e22e8fa8490039889d07"},"schema_version":"1.0"},"canonical_sha256":"a29a308749ff37483797b96f7b834913ddf8619d3266d055de635de3842c8634","source":{"kind":"arxiv","id":"1112.4349","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1112.4349","created_at":"2026-05-18T01:59:05Z"},{"alias_kind":"arxiv_version","alias_value":"1112.4349v1","created_at":"2026-05-18T01:59:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1112.4349","created_at":"2026-05-18T01:59:05Z"},{"alias_kind":"pith_short_12","alias_value":"UKNDBB2J743U","created_at":"2026-05-18T12:26:42Z"},{"alias_kind":"pith_short_16","alias_value":"UKNDBB2J743UQN4X","created_at":"2026-05-18T12:26:42Z"},{"alias_kind":"pith_short_8","alias_value":"UKNDBB2J","created_at":"2026-05-18T12:26:42Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2011:UKNDBB2J743UQN4XXFXXXA2JCP","target":"record","payload":{"canonical_record":{"source":{"id":"1112.4349","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-12-19T14:35:19Z","cross_cats_sorted":[],"title_canon_sha256":"0e7dbca621ffd00a88a1fd57793dacda21a46891123a085042c67a0314b55701","abstract_canon_sha256":"58934c6b5417732a04af2f3cb2426943d0c013ad1464e22e8fa8490039889d07"},"schema_version":"1.0"},"canonical_sha256":"a29a308749ff37483797b96f7b834913ddf8619d3266d055de635de3842c8634","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:59:05.630760Z","signature_b64":"FBLwt950NJyYpNmWRnKWSR4mN/7bb/6hOqIf4+jkkf/DIPrKV7px8BZcp71OjpdSr1WPFBwLxtUQvQwCjF6DAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a29a308749ff37483797b96f7b834913ddf8619d3266d055de635de3842c8634","last_reissued_at":"2026-05-18T01:59:05.630085Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:59:05.630085Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1112.4349","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":"2026-05-18T01:59:05Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"AX5vn9SBQt1bQEJkrofJzwIOJELQc033GRYtWV9PO7rKQfJyDNVbzbROc601rh5/m7cQj927clQs2ggaDU6sDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-02T05:55:02.709478Z"},"content_sha256":"7e81d2b6419f49ec481b7c13dc4b9c8f4c71d0c435a9f9a63a4bfd7979a09553","schema_version":"1.0","event_id":"sha256:7e81d2b6419f49ec481b7c13dc4b9c8f4c71d0c435a9f9a63a4bfd7979a09553"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2011:UKNDBB2J743UQN4XXFXXXA2JCP","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"XMM-Newton observation of 4U 1820-30: Broad band spectrum and the contribution of the cold interstellar medium","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"2), (2) Univ. of Utrecht, (3) MPE, (4) Univ. of Groningen, 5) ((1) SRON, (5) UvA), C. P. de Vries (1), C. Pinto (1), E. Costantini (1), J. J. M. in't Zand (1), J. S. Kaastra (1, L. B. F. M. Waters (1, L. Kuiper (1), M. J. Freyberg (3), M. Mendez (4)","submitted_at":"2011-12-19T14:35:19Z","abstract_excerpt":"We present the analysis of the bright X-ray binary 4U 1820-30, based mainly on XMM-Newton-RGS data, but using complementary data from XMM-Epic, Integral, and Chandra-HETG, to investigate different aspects of the source. The broad band continuum is well fitted by a classical combination of black body and Comptonized emission. The continuum shape and the high flux of the source (L/L_Edd\\sim0.16) are consistent with a \"high state\" of the source. We do not find significant evidence of iron emission at energies >=6.4 keV. The soft X-ray spectrum contain a number of absorption features. Here we focu"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1112.4349","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":"2026-05-18T01:59:05Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4aQ4u8h5Oz1cck4tBzisFtYBAuyWk8Jeqvwd1vlMytFg6vFlZlN/1J3Ay06aMqmbcuNp2lAgYwch7At2VLpQAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-02T05:55:02.709836Z"},"content_sha256":"f88453922894968d715bc3e5b70e04660b5ba6eaa3d0e69a555ec7d70d8690c8","schema_version":"1.0","event_id":"sha256:f88453922894968d715bc3e5b70e04660b5ba6eaa3d0e69a555ec7d70d8690c8"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/UKNDBB2J743UQN4XXFXXXA2JCP/bundle.json","state_url":"https://pith.science/pith/UKNDBB2J743UQN4XXFXXXA2JCP/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/UKNDBB2J743UQN4XXFXXXA2JCP/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":"2026-07-02T05:55:02Z","links":{"resolver":"https://pith.science/pith/UKNDBB2J743UQN4XXFXXXA2JCP","bundle":"https://pith.science/pith/UKNDBB2J743UQN4XXFXXXA2JCP/bundle.json","state":"https://pith.science/pith/UKNDBB2J743UQN4XXFXXXA2JCP/state.json","well_known_bundle":"https://pith.science/.well-known/pith/UKNDBB2J743UQN4XXFXXXA2JCP/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:UKNDBB2J743UQN4XXFXXXA2JCP","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":"58934c6b5417732a04af2f3cb2426943d0c013ad1464e22e8fa8490039889d07","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-12-19T14:35:19Z","title_canon_sha256":"0e7dbca621ffd00a88a1fd57793dacda21a46891123a085042c67a0314b55701"},"schema_version":"1.0","source":{"id":"1112.4349","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1112.4349","created_at":"2026-05-18T01:59:05Z"},{"alias_kind":"arxiv_version","alias_value":"1112.4349v1","created_at":"2026-05-18T01:59:05Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1112.4349","created_at":"2026-05-18T01:59:05Z"},{"alias_kind":"pith_short_12","alias_value":"UKNDBB2J743U","created_at":"2026-05-18T12:26:42Z"},{"alias_kind":"pith_short_16","alias_value":"UKNDBB2J743UQN4X","created_at":"2026-05-18T12:26:42Z"},{"alias_kind":"pith_short_8","alias_value":"UKNDBB2J","created_at":"2026-05-18T12:26:42Z"}],"graph_snapshots":[{"event_id":"sha256:f88453922894968d715bc3e5b70e04660b5ba6eaa3d0e69a555ec7d70d8690c8","target":"graph","created_at":"2026-05-18T01:59:05Z","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 the analysis of the bright X-ray binary 4U 1820-30, based mainly on XMM-Newton-RGS data, but using complementary data from XMM-Epic, Integral, and Chandra-HETG, to investigate different aspects of the source. The broad band continuum is well fitted by a classical combination of black body and Comptonized emission. The continuum shape and the high flux of the source (L/L_Edd\\sim0.16) are consistent with a \"high state\" of the source. We do not find significant evidence of iron emission at energies >=6.4 keV. The soft X-ray spectrum contain a number of absorption features. Here we focu","authors_text":"2), (2) Univ. of Utrecht, (3) MPE, (4) Univ. of Groningen, 5) ((1) SRON, (5) UvA), C. P. de Vries (1), C. Pinto (1), E. Costantini (1), J. J. M. in't Zand (1), J. S. Kaastra (1, L. B. F. M. Waters (1, L. Kuiper (1), M. J. Freyberg (3), M. Mendez (4)","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-12-19T14:35:19Z","title":"XMM-Newton observation of 4U 1820-30: Broad band spectrum and the contribution of the cold interstellar medium"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1112.4349","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":"sha256:7e81d2b6419f49ec481b7c13dc4b9c8f4c71d0c435a9f9a63a4bfd7979a09553","target":"record","created_at":"2026-05-18T01:59:05Z","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":"58934c6b5417732a04af2f3cb2426943d0c013ad1464e22e8fa8490039889d07","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2011-12-19T14:35:19Z","title_canon_sha256":"0e7dbca621ffd00a88a1fd57793dacda21a46891123a085042c67a0314b55701"},"schema_version":"1.0","source":{"id":"1112.4349","kind":"arxiv","version":1}},"canonical_sha256":"a29a308749ff37483797b96f7b834913ddf8619d3266d055de635de3842c8634","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a29a308749ff37483797b96f7b834913ddf8619d3266d055de635de3842c8634","first_computed_at":"2026-05-18T01:59:05.630085Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:59:05.630085Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"FBLwt950NJyYpNmWRnKWSR4mN/7bb/6hOqIf4+jkkf/DIPrKV7px8BZcp71OjpdSr1WPFBwLxtUQvQwCjF6DAw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:59:05.630760Z","signed_message":"canonical_sha256_bytes"},"source_id":"1112.4349","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:7e81d2b6419f49ec481b7c13dc4b9c8f4c71d0c435a9f9a63a4bfd7979a09553","sha256:f88453922894968d715bc3e5b70e04660b5ba6eaa3d0e69a555ec7d70d8690c8"],"state_sha256":"9625998337d979db2d3f6c95f84dfb5e36e7441bdf2a35a2dda423cacf071bd8"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"2ER3vk1lzYZmUEu5rZx+JhVVN9dpNAhXUTTy3/p4ak4vpJ9y7vkcC7kqO4/sBSwhxRgBcjp2Q6A5yBOcl9GKDg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-02T05:55:02.711795Z","bundle_sha256":"c4d696d0d96e4284a39ebf9320dc62e72d466419807bf8fc4532dd97a922bfdc"}}