Timing and Spectral Performance of INTEGRAL/PICsIT for GRB Detections at Large Off-axis Angles

Following the exciting detection of GW170817/GRB170817A at the end of LIGO-Virgo observing run O2, expectations were high for detecting multiple electromagnetic (EM) counterparts to gravitational wave triggers during O3. Using its spectral-timing data (7.8-ms time resolution), the soft gamma-ray detector (200 keV to 2.6 MeV) on board INTEGRAL, PICsIT, is capable of detecting gamma-ray bursts (GRBs) even outside its imaging field-of-view (FoV), thus effectively operating as a soft gamma-ray all-sky monitor. To prepare for the possibility that an EM counterpart is observed outside the imaging FoV, we have analyzed GRB spectra seen by Fermi/GBM and PICsIT at various incident angles to characterize the instrument off-axis response. We present the results of our joint analysis.