The first GRB survey of the IBIS/PICsIT archive

Abstract

Context. The multi-purpose INTEGRAL mission is continuously contributing to Gamma Ray Burst (GRB) science, thanks to the performances of its two main instruments, IBIS and SPI, operating in the hard X-ray / soft γ-ray domain. Aims. We investigate the possibilities offered to the study of GRBs by PICsIT, the high-energy detector of the IBIS instrument. Methods. We searched for transient episodes in the PICsIT light curves archive from May 2006 to August 2009, using stringent criteria optimized for the detection of long events. In the time interval under examination PICsIT provides an energy coverage from 208 to 2600 keV, resolved in eight energy channels, combined with a fine time resolution of 16 ms. Results. PICsIT successfully observes GRBs in the 260-2600 keV energy range with an incoming direction spread over half the sky for the brightest events. We compiled a list of 39 bursts, most of which are confirmed GRBs or simultaneous to triggers from other satellites/instruments. We produced light curves with a time sampling down to 0.25 s in three energy intervals for all events. Because an adequate response matrix is not yet available for the PICsIT burst sample, we obtained a calibration coefficient in three selected energy bands by comparing instrumental counts with physical fluences inferred from observations with different satellites. The good time resolution provided by the PICsIT data allows a spectral variability study of our sample through the hardness ratio.

New Gamma-Ray Bursts Found in the Archival Data from the IBIS/ISGRI Telescope of the INTEGRAL Observatory

“…The localization of events was not possible in this case. Bianchin et al (2011) analyzed the accessible data from this detector obtained from May 2006 to August 2009 and revealed 39 events, 23 of which were previously observed in other experiments.…”

“…The selected events from catalog 1 non-coincident with IBAS bursts were then checked (within ±50 s) against the catalogs of bursts recorded by the SPI gamma-ray spectrometer (Minaev et al 2012(Minaev et al , 2014, its shield SPI/ACS 2 , the IBIS/PICsIT gamma-ray detector (Bianchin et al 2011) of the INTEGRAL observatory as well as the master list of cosmic GRBs from all missions (Hurley 2010) 3 and the list of events recorded from soft gamma repeaters 4 . It turned out that four bursts from catalog 1 were known previously -these are the already mentioned GRB 070912 (Minaev et al 2012) and three bursts recorded in the KONUS/WIND 5 experiment: GRB 130109, GRB 150704, and GRB 180118 (Tsvetkova et al 2017;Frederiks et al 2019).…”

Soft gamma-ray spectral and time evolution of the GRB 221009A: Prompt and afterglow emission with INTEGRAL/IBIS-PICsIT

“…In contrast, the spectral-imaging data type sums the counts in each pixel over the span of an INTEGRAL pointing (∼ 1800 s). Using the spectral-timing data, PICsIT is able to detect impulsive events both inside and outside the FoV (Bianchin et al 2009(Bianchin et al , 2011Savchenko et al 2017), though with reduced sensitivity for those outside the shielding of the IBIS walls. It is possible to account for the absorbing materials to also produce spectra (Bianchin et al 2009;Rodi et al 2021).…”

Effects of nonlinear electrodynamics in the magnetic field of a pulsar

“…These characteristic features [38] acquired as a result of nonlinear exposure to the strong dipole magnetic fields of pulsars may in some cases be detected by spacecraft-based experiments. X-ray and gamma radiation coming to the Earth from pulsars are the focus of various satellite-based experiments, such as the Rossi X-ray Timing Explorer (RXTE) [39], the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) [40], and the Large Observatory for X-ray Timing (LOFT) [41].…”