{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2012:RSCN76CR2JVXO7MLNJHTQWRZNT","short_pith_number":"pith:RSCN76CR","schema_version":"1.0","canonical_sha256":"8c84dff851d26b777d8b6a4f385a396cfe23f715b4974f3d3ff69dd1cc7e2ee4","source":{"kind":"arxiv","id":"1211.6215","version":1},"attestation_state":"computed","paper":{"title":"The JHU-SDSS metal absorption line catalog: redshift evolution and properties of Mg II absorbers","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.CO","authors_text":"Brice M\\'enard (JHU), Guangtun Zhu","submitted_at":"2012-11-27T05:40:41Z","abstract_excerpt":"We present a generic and fully-automatic method aimed at detecting absorption lines in the spectra of astronomical objects. The algorithm estimates the source continuum flux using a dimensionality reduction technique, nonnegative matrix factorization, and then detects and identifies metal absorption lines. We apply it to a sample of ~100,000 quasar spectra from the Sloan Digital Sky Survey and compile a sample of ~40,000 Mg II & Fe II absorber systems, spanning the redshift range 0.4< z < 2.3. The corresponding catalog is publicly available. We study the statistical properties of these absorbe"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1211.6215","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2012-11-27T05:40:41Z","cross_cats_sorted":["astro-ph.IM"],"title_canon_sha256":"48b7bc70dfbbfccd1d08c32e5a57271ac51d0109f47279ce6f6d0678743afa74","abstract_canon_sha256":"cf7419d4db4b4d9962c7d15d3e777ff8acc72c8c73102ff23ba4b2b1f2930881"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:52:54.609119Z","signature_b64":"HOFglbuXzczR+isUpZz9QDxVaTmfZP1+1O823S28/+Lw76whPWZT+scpmeWlXVNSF6h73MRe4ERecSaAO2KNBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"8c84dff851d26b777d8b6a4f385a396cfe23f715b4974f3d3ff69dd1cc7e2ee4","last_reissued_at":"2026-05-18T01:52:54.608611Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:52:54.608611Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"The JHU-SDSS metal absorption line catalog: redshift evolution and properties of Mg II absorbers","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.IM"],"primary_cat":"astro-ph.CO","authors_text":"Brice M\\'enard (JHU), Guangtun Zhu","submitted_at":"2012-11-27T05:40:41Z","abstract_excerpt":"We present a generic and fully-automatic method aimed at detecting absorption lines in the spectra of astronomical objects. The algorithm estimates the source continuum flux using a dimensionality reduction technique, nonnegative matrix factorization, and then detects and identifies metal absorption lines. We apply it to a sample of ~100,000 quasar spectra from the Sloan Digital Sky Survey and compile a sample of ~40,000 Mg II & Fe II absorber systems, spanning the redshift range 0.4< z < 2.3. The corresponding catalog is publicly available. We study the statistical properties of these absorbe"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1211.6215","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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1211.6215","created_at":"2026-05-18T01:52:54.608684+00:00"},{"alias_kind":"arxiv_version","alias_value":"1211.6215v1","created_at":"2026-05-18T01:52:54.608684+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1211.6215","created_at":"2026-05-18T01:52:54.608684+00:00"},{"alias_kind":"pith_short_12","alias_value":"RSCN76CR2JVX","created_at":"2026-05-18T12:27:20.899486+00:00"},{"alias_kind":"pith_short_16","alias_value":"RSCN76CR2JVXO7ML","created_at":"2026-05-18T12:27:20.899486+00:00"},{"alias_kind":"pith_short_8","alias_value":"RSCN76CR","created_at":"2026-05-18T12:27:20.899486+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":1,"internal_anchor_count":0,"sample":[{"citing_arxiv_id":"2604.17534","citing_title":"A Giant Ring on the sky","ref_index":9,"is_internal_anchor":false}]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT","json":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT.json","graph_json":"https://pith.science/api/pith-number/RSCN76CR2JVXO7MLNJHTQWRZNT/graph.json","events_json":"https://pith.science/api/pith-number/RSCN76CR2JVXO7MLNJHTQWRZNT/events.json","paper":"https://pith.science/paper/RSCN76CR"},"agent_actions":{"view_html":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT","download_json":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT.json","view_paper":"https://pith.science/paper/RSCN76CR","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1211.6215&json=true","fetch_graph":"https://pith.science/api/pith-number/RSCN76CR2JVXO7MLNJHTQWRZNT/graph.json","fetch_events":"https://pith.science/api/pith-number/RSCN76CR2JVXO7MLNJHTQWRZNT/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT/action/timestamp_anchor","attest_storage":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT/action/storage_attestation","attest_author":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT/action/author_attestation","sign_citation":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT/action/citation_signature","submit_replication":"https://pith.science/pith/RSCN76CR2JVXO7MLNJHTQWRZNT/action/replication_record"}},"created_at":"2026-05-18T01:52:54.608684+00:00","updated_at":"2026-05-18T01:52:54.608684+00:00"}