{"paper":{"title":"Detectability of Polarized Gamma-ray Emission from Blazar Flares with COSI","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"COSI can detect MeV polarization from up to six blazar flares in two years.","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Alberto Sciaccaluga, Andreas Zoglauer, Carolyn A. Kierans, Christopher M. Karwin, Daniel Kocevski, Dieter H. Hartmann, Garrett A. Latiolais, Haocheng Zhang, Ioannis Liodakis, Israel Martinez-Castellanos, John A. Tomsick, Jorge Otero-Santos, Lea Marcotulli, Marco Ajello, Michela Negro, Mohammad Ali Boroumand, Sara Capecchiacci, Savitri Gallego, Srinadh R. Bhavanam, Steven E. Boggs, Tiffany R. Lewis","submitted_at":"2026-05-01T22:31:25Z","abstract_excerpt":"We investigate the detectability of polarized gamma-ray emission from blazar flares with the Compton Spectrometer and Imager (COSI). Using 17 years of Fermi Large Area Telescope observations, we analyze light curves for 1413 blazars and identify a maximum of 787 sources with flaring episodes through Bayesian block analysis. For each flare, we estimate the minimum detectable polarization MDP99 in the COSI energy band (0.2-5 MeV) using instrument response functions under a range of spectral assumptions and background conditions. Under baseline background levels (1 counts/s), and assuming that bl"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Under baseline background levels (1 counts/s), and assuming that blazar flare statistics in the MeV band are comparable to those observed at GeV energies, we find that COSI can realistically detect polarization in up to ~6 flares with MDP99<50% over its two-year prime mission depending on different spectral and flare identification assumptions, with only a few most powerful ones reaching MDP99<20%.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"assuming that blazar flare statistics in the MeV band are comparable to those observed at GeV energies","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"COSI is projected to detect MeV polarization from up to about 6 blazar flares over its two-year mission, mostly flat-spectrum radio quasars, assuming GeV-like flare rates and baseline backgrounds.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"COSI can detect MeV polarization from up to six blazar flares in two years.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"4e9a8bd482a4284ad3a6e221e18ca566601f0b4c11130b416b6f54ab7d857ea9"},"source":{"id":"2605.01139","kind":"arxiv","version":2},"verdict":{"id":"ddef400a-e698-4ebe-a972-0c3cb8aa6db3","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-09T18:11:48.777181Z","strongest_claim":"Under baseline background levels (1 counts/s), and assuming that blazar flare statistics in the MeV band are comparable to those observed at GeV energies, we find that COSI can realistically detect polarization in up to ~6 flares with MDP99<50% over its two-year prime mission depending on different spectral and flare identification assumptions, with only a few most powerful ones reaching MDP99<20%.","one_line_summary":"COSI is projected to detect MeV polarization from up to about 6 blazar flares over its two-year mission, mostly flat-spectrum radio quasars, assuming GeV-like flare rates and baseline backgrounds.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"assuming that blazar flare statistics in the MeV band are comparable to those observed at GeV energies","pith_extraction_headline":"COSI can detect MeV polarization from up to six blazar flares in two years."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2605.01139/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-20T18:38:17.433673Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T17:32:34.048239Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"e4b3596eb25af0547e12c1b07692bdafdd71c7ef9c0df6383ed0adf95c3152e5"},"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"}