Detectability of Polarized Gamma-ray Emission from Blazar Flares with COSI
Garrett A. Latiolais, Jorge Otero-Santos, Michela Negro, Lea Marcotulli, Mohammad Ali Boroumand, Savitri Gallego, Christopher M. Karwin, Israel Martinez-Castellanos, Daniel Kocevski, Marco Ajello, Sara Capecchiacci, Ioannis Liodakis, Srinadh R. Bhavanam, Steven E. Boggs, Dieter H. Hartmann, Carolyn A. Kierans, Tiffany R. Lewis, Alberto Sciaccaluga, John A. Tomsick, Haocheng Zhang, Andreas Zoglauer
arXiv:2605.01139v2 Announce Type: replace
Abstract: 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 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 MDP99arXiv:2605.01139v2 Announce Type: replace
Abstract: 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 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