{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2017:BNP5LF62W6LAD53QLAZ3XIZN2C","short_pith_number":"pith:BNP5LF62","canonical_record":{"source":{"id":"1707.09202","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-07-28T12:08:53Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"fe6c36fff608a6cbebb2163a0556be7b795a6c3668b75185ae1b141f8b7f0905","abstract_canon_sha256":"27c19f52606b700798a8574d69d7027498e2c8ad41504148acd95f393d6b5228"},"schema_version":"1.0"},"canonical_sha256":"0b5fd597dab79601f7705833bba32dd089593cc20e65b9e38ad76b2fd96d37d8","source":{"kind":"arxiv","id":"1707.09202","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1707.09202","created_at":"2026-05-18T00:35:19Z"},{"alias_kind":"arxiv_version","alias_value":"1707.09202v1","created_at":"2026-05-18T00:35:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1707.09202","created_at":"2026-05-18T00:35:19Z"},{"alias_kind":"pith_short_12","alias_value":"BNP5LF62W6LA","created_at":"2026-05-18T12:31:08Z"},{"alias_kind":"pith_short_16","alias_value":"BNP5LF62W6LAD53Q","created_at":"2026-05-18T12:31:08Z"},{"alias_kind":"pith_short_8","alias_value":"BNP5LF62","created_at":"2026-05-18T12:31:08Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2017:BNP5LF62W6LAD53QLAZ3XIZN2C","target":"record","payload":{"canonical_record":{"source":{"id":"1707.09202","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-07-28T12:08:53Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"fe6c36fff608a6cbebb2163a0556be7b795a6c3668b75185ae1b141f8b7f0905","abstract_canon_sha256":"27c19f52606b700798a8574d69d7027498e2c8ad41504148acd95f393d6b5228"},"schema_version":"1.0"},"canonical_sha256":"0b5fd597dab79601f7705833bba32dd089593cc20e65b9e38ad76b2fd96d37d8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:35:19.361025Z","signature_b64":"SYu2uTiT8UfIvf4UsAw0v3Xvmp2VqXFh0CXNRjfg857hmk0G1beQpQfViqU/LN2RDjSS/ehot3rZaHuSXodZCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"0b5fd597dab79601f7705833bba32dd089593cc20e65b9e38ad76b2fd96d37d8","last_reissued_at":"2026-05-18T00:35:19.360559Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:35:19.360559Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1707.09202","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":"2026-05-18T00:35:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"GZU1wC3k5ZxRBmD2asgJ1kQRGHwe6CCxxa8vkVmoNt+GSa92v/mNp4BTpiHOfPCMkkFKpnt1itl7c9u8rFY/BA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T17:17:44.057696Z"},"content_sha256":"148399b3091a500489c70ba67bf9018410e9e1858f535f07b20658832bf6654f","schema_version":"1.0","event_id":"sha256:148399b3091a500489c70ba67bf9018410e9e1858f535f07b20658832bf6654f"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2017:BNP5LF62W6LAD53QLAZ3XIZN2C","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"On the use of C-stat in testing models for X-ray spectra","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.HE","authors_text":"J.S. Kaastra","submitted_at":"2017-07-28T12:08:53Z","abstract_excerpt":"It has been shown that for the analysis of X-ray spectra the C-statistic, contrary to the chi^2-statistic, provides unbiased estimates of the model parameters and their uncertainty ranges. However, it is often stated that the C-statistic cannot be used to carry out statistical tests on the goodness of fit of the model, and therefore several investigations are still based on chi^2-statistics. Here we show that it is straightforward to calculate the expected value and variance of the C-statistic so that it can be used in tests. We provide formulae and simple numerical approximations to evaluate "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1707.09202","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":"2026-05-18T00:35:19Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"sqhVuAck87DrmkNtIb7RVATn/mBK1NjHm01fqBqGdJ97M/YOf04mVP4aYSB+xuCrv2Uu+1RCWMcGZ6hgo991CQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T17:17:44.058404Z"},"content_sha256":"0b7d108934f6f921dfb61c33b9bc362a83c68af8256b5b928c0d6350a883ec48","schema_version":"1.0","event_id":"sha256:0b7d108934f6f921dfb61c33b9bc362a83c68af8256b5b928c0d6350a883ec48"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/BNP5LF62W6LAD53QLAZ3XIZN2C/bundle.json","state_url":"https://pith.science/pith/BNP5LF62W6LAD53QLAZ3XIZN2C/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/BNP5LF62W6LAD53QLAZ3XIZN2C/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":"2026-05-25T17:17:44Z","links":{"resolver":"https://pith.science/pith/BNP5LF62W6LAD53QLAZ3XIZN2C","bundle":"https://pith.science/pith/BNP5LF62W6LAD53QLAZ3XIZN2C/bundle.json","state":"https://pith.science/pith/BNP5LF62W6LAD53QLAZ3XIZN2C/state.json","well_known_bundle":"https://pith.science/.well-known/pith/BNP5LF62W6LAD53QLAZ3XIZN2C/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:BNP5LF62W6LAD53QLAZ3XIZN2C","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":"27c19f52606b700798a8574d69d7027498e2c8ad41504148acd95f393d6b5228","cross_cats_sorted":["astro-ph.IM"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-07-28T12:08:53Z","title_canon_sha256":"fe6c36fff608a6cbebb2163a0556be7b795a6c3668b75185ae1b141f8b7f0905"},"schema_version":"1.0","source":{"id":"1707.09202","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1707.09202","created_at":"2026-05-18T00:35:19Z"},{"alias_kind":"arxiv_version","alias_value":"1707.09202v1","created_at":"2026-05-18T00:35:19Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1707.09202","created_at":"2026-05-18T00:35:19Z"},{"alias_kind":"pith_short_12","alias_value":"BNP5LF62W6LA","created_at":"2026-05-18T12:31:08Z"},{"alias_kind":"pith_short_16","alias_value":"BNP5LF62W6LAD53Q","created_at":"2026-05-18T12:31:08Z"},{"alias_kind":"pith_short_8","alias_value":"BNP5LF62","created_at":"2026-05-18T12:31:08Z"}],"graph_snapshots":[{"event_id":"sha256:0b7d108934f6f921dfb61c33b9bc362a83c68af8256b5b928c0d6350a883ec48","target":"graph","created_at":"2026-05-18T00:35:19Z","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":"It has been shown that for the analysis of X-ray spectra the C-statistic, contrary to the chi^2-statistic, provides unbiased estimates of the model parameters and their uncertainty ranges. However, it is often stated that the C-statistic cannot be used to carry out statistical tests on the goodness of fit of the model, and therefore several investigations are still based on chi^2-statistics. Here we show that it is straightforward to calculate the expected value and variance of the C-statistic so that it can be used in tests. We provide formulae and simple numerical approximations to evaluate ","authors_text":"J.S. Kaastra","cross_cats":["astro-ph.IM"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-07-28T12:08:53Z","title":"On the use of C-stat in testing models for X-ray spectra"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1707.09202","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":"sha256:148399b3091a500489c70ba67bf9018410e9e1858f535f07b20658832bf6654f","target":"record","created_at":"2026-05-18T00:35:19Z","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":"27c19f52606b700798a8574d69d7027498e2c8ad41504148acd95f393d6b5228","cross_cats_sorted":["astro-ph.IM"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.HE","submitted_at":"2017-07-28T12:08:53Z","title_canon_sha256":"fe6c36fff608a6cbebb2163a0556be7b795a6c3668b75185ae1b141f8b7f0905"},"schema_version":"1.0","source":{"id":"1707.09202","kind":"arxiv","version":1}},"canonical_sha256":"0b5fd597dab79601f7705833bba32dd089593cc20e65b9e38ad76b2fd96d37d8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"0b5fd597dab79601f7705833bba32dd089593cc20e65b9e38ad76b2fd96d37d8","first_computed_at":"2026-05-18T00:35:19.360559Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:35:19.360559Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"SYu2uTiT8UfIvf4UsAw0v3Xvmp2VqXFh0CXNRjfg857hmk0G1beQpQfViqU/LN2RDjSS/ehot3rZaHuSXodZCQ==","signature_status":"signed_v1","signed_at":"2026-05-18T00:35:19.361025Z","signed_message":"canonical_sha256_bytes"},"source_id":"1707.09202","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:148399b3091a500489c70ba67bf9018410e9e1858f535f07b20658832bf6654f","sha256:0b7d108934f6f921dfb61c33b9bc362a83c68af8256b5b928c0d6350a883ec48"],"state_sha256":"78d0ae2b68317a73d5d535360eaa4d5d508642fd2514633176b90b053153aa55"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ekyMmDxty/NS6BrVn8mCJpuOJbHCzIsc5ELQO/gplddwGjR75EQcOIVLXgQMkDpFU7UiG8xW97nJA+Vy0nSCAQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T17:17:44.061431Z","bundle_sha256":"8a478c45cb194750b4f2e5fa574a32590d6f9b23991614398cb9461965e998ed"}}