{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2021:WDCHPTFVXPCP3G7HERL5LB5TF6","short_pith_number":"pith:WDCHPTFV","schema_version":"1.0","canonical_sha256":"b0c477ccb5bbc4fd9be72457d587b32fa1f032abc8b33c742d7f70127c79772a","source":{"kind":"arxiv","id":"2109.07856","version":1},"attestation_state":"computed","paper":{"title":"Extremely weak CO emission in IZw 18","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Junzhi Wang, Luwenjia Zhou, Yong Shi, Zhi-Yu Zhang","submitted_at":"2021-09-16T10:37:56Z","abstract_excerpt":"Local metal-poor galaxies are ideal analogues of primordial galaxies with the interstellar medium (ISM) barely being enriched with metals. However, it is unclear whether carbon monoxide remains a good tracer and coolant of molecular gas at low metallicity. Based on the observation with the upgraded Northern Extended Millimeter Array (NOEMA), we report a marginal detection of CO $J$=2-1 emission in IZw18, pushing the detection limit down to $L^\\prime_{\\rm CO(2-1)}$=3.99$\\times$10$^3$ K km$^{-1}$pc$^{-2}$, which is at least 40 times lower than previous studies. As one of the most metal-poor gala"},"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":"2109.07856","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.GA","submitted_at":"2021-09-16T10:37:56Z","cross_cats_sorted":[],"title_canon_sha256":"0986294a14910e7c5747209b9c4551bc8a89ed14cd73f7ae9aaebefb0313fad6","abstract_canon_sha256":"361a3c766c928dc3ee6e38a680cfaa782523cdd0b051fc1d98c27dc1ebcc74b8"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:18:22.139418Z","signature_b64":"5Wq1g3xcJAKVObvuTsPLyZKM8yiCmJfMb+FJ7Rf5SAscZLAo6HvVpSZx1/5H4UAJsx0I+ugWCaY3v4bp5pLPDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b0c477ccb5bbc4fd9be72457d587b32fa1f032abc8b33c742d7f70127c79772a","last_reissued_at":"2026-07-05T03:18:22.139022Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:18:22.139022Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Extremely weak CO emission in IZw 18","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"Junzhi Wang, Luwenjia Zhou, Yong Shi, Zhi-Yu Zhang","submitted_at":"2021-09-16T10:37:56Z","abstract_excerpt":"Local metal-poor galaxies are ideal analogues of primordial galaxies with the interstellar medium (ISM) barely being enriched with metals. However, it is unclear whether carbon monoxide remains a good tracer and coolant of molecular gas at low metallicity. Based on the observation with the upgraded Northern Extended Millimeter Array (NOEMA), we report a marginal detection of CO $J$=2-1 emission in IZw18, pushing the detection limit down to $L^\\prime_{\\rm CO(2-1)}$=3.99$\\times$10$^3$ K km$^{-1}$pc$^{-2}$, which is at least 40 times lower than previous studies. As one of the most metal-poor gala"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2109.07856","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2109.07856/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2109.07856","created_at":"2026-07-05T03:18:22.139075+00:00"},{"alias_kind":"arxiv_version","alias_value":"2109.07856v1","created_at":"2026-07-05T03:18:22.139075+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2109.07856","created_at":"2026-07-05T03:18:22.139075+00:00"},{"alias_kind":"pith_short_12","alias_value":"WDCHPTFVXPCP","created_at":"2026-07-05T03:18:22.139075+00:00"},{"alias_kind":"pith_short_16","alias_value":"WDCHPTFVXPCP3G7H","created_at":"2026-07-05T03:18:22.139075+00:00"},{"alias_kind":"pith_short_8","alias_value":"WDCHPTFV","created_at":"2026-07-05T03:18:22.139075+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6","json":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6.json","graph_json":"https://pith.science/api/pith-number/WDCHPTFVXPCP3G7HERL5LB5TF6/graph.json","events_json":"https://pith.science/api/pith-number/WDCHPTFVXPCP3G7HERL5LB5TF6/events.json","paper":"https://pith.science/paper/WDCHPTFV"},"agent_actions":{"view_html":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6","download_json":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6.json","view_paper":"https://pith.science/paper/WDCHPTFV","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=2109.07856&json=true","fetch_graph":"https://pith.science/api/pith-number/WDCHPTFVXPCP3G7HERL5LB5TF6/graph.json","fetch_events":"https://pith.science/api/pith-number/WDCHPTFVXPCP3G7HERL5LB5TF6/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6/action/timestamp_anchor","attest_storage":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6/action/storage_attestation","attest_author":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6/action/author_attestation","sign_citation":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6/action/citation_signature","submit_replication":"https://pith.science/pith/WDCHPTFVXPCP3G7HERL5LB5TF6/action/replication_record"}},"created_at":"2026-07-05T03:18:22.139075+00:00","updated_at":"2026-07-05T03:18:22.139075+00:00"}