Observation of Anomalous Electron Fluxes Induced by GRB221009A on CSES-01 Low-energy Charged Particle Detector

Abstract

High-energy, long gamma-ray bursts (GRBs) can be generated by the core collapse of massive stars at the end of their lives. When they happen in the close-by universe they can be exceptionally bright, as seen from the Earth in the case of the recent, giant, long-lasting GRB221009A. GRB221009A was produced by a collapsing star with a redshift of 0.152: this event was observed by many gamma-ray space experiments, which also detected an extraordinary long gamma-ray afterglow. The exceptionally large fluence of the prompt emission of about 0.013 erg cm−2 illuminated a large geographical region centered on India and including Europe and Asia. We report in this paper the observation of sudden electron flux changes correlated with GRB221009A and measured by the HEPP-L charged particle detector on board the China Seismo-Electromagnetic Satellite, which was orbiting over Europe at the time of the GRB event. The time structure of the observed electron flux closely matches the very distinctive time dependence of the photon flux associated with the main part of the emission at around 13:20 UTC on 2022 October 9. To test the origin of these signals, we set up a simplified simulation of one HEPP-L subdetector: the results of this analysis suggest that the signals observed are mostly due to electrons created within the aluminum collimator surrounding the silicon detector, providing real-time monitoring of the very intense photon fluxes. We discuss the implications of this observation for existing and forthcoming particle detectors on low Earth orbits.

First Detection of the Powerful Gamma-Ray Burst GRB 221009A by the THEMIS ESA and SST Particle Detectors on 2022 October 9

“…The ARTEMIS spacecraft THB and THC carried particles measurements in the same mode: spin-resolution ESA and spin- +219 s for the shoulder, T0+225 s for the first peak, T0+256 s for the second peak, and T0+509 for third peak are indicated by the vertical dashed lines). The timing uncertainties of THEMIS spacecraft synchronization (∼0.1 s) and time resolution do not allow us to resolve the time shift between the GRB signal recorded on board THB and THE and the data recorded on board the LEO spacecraft presented in detail by Battiston et al (2023). Thus, we present a 1 s resolution version of the ESA and SST data to compare with the 1 s light curves of HEPP-L (Battiston et al 2023) and HEBS (Liu et al 2022).…”

“…These measurements from spacecraft particle detectors provide an alternative perspective that complements observations from the gamma-ray telescopes by providing high sampling rates capable of resolving the fine structure of bursts (Schwartz et al 2005;Terasawa et al 2005). GRB 221009A was detected in the electron flux measurements made by the HEPP-L charged particle detector on board the low Earth orbit (LEO) China Seismo-Electromagnetic Satellite (Battiston et al 2023). Battiston et al (2023) showed that the recorded anomalous signal of GRB 221009A in the electron fluxes originated from secondary electrons produced via photon absorption in the passive material of the detector.…”

“…GRB 221009A was detected in the electron flux measurements made by the HEPP-L charged particle detector on board the low Earth orbit (LEO) China Seismo-Electromagnetic Satellite (Battiston et al 2023). Battiston et al (2023) showed that the recorded anomalous signal of GRB 221009A in the electron fluxes originated from secondary electrons produced via photon absorption in the passive material of the detector. The signal dynamics followed quite well the structure of the GRB 221009A signal recorded by HEBS (Liu et al 2022).…”

“…The signal dynamics followed quite well the structure of the GRB 221009A signal recorded by HEBS (Liu et al 2022). Here we report observations of the fine structure of the GRB 221009A gamma burst signal recorded in electron and proton flux measurements (the bursts of secondary electrons produced through interactions of gamma photons with material of the detectors Battiston et al 2023) by the electrostatic analyzers ESA (McFadden et al 2008) and solid-state telescopes (SSTs) on board the four (of the five) THEMIS spacecraft (Angelo-poulos2014) on 2022 October 9. The configuration of the spacecraft is shown in Figure 1.…”

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

“…The observation of the prompt emission was initially reported by Fermi/GBM (T 0 = 13:17:00 UTC) (Veres et al 2022). In view of the extreme GRB flux, spanning from low-energy X-rays to very high gamma rays, detections were reported by numerous instruments, including detectors not built to detect GRBs such as GAIA, SOHO (ESA 2022), Solar Orbiter (Xiao et al 2022), CSES HPPL (Battiston et al 2023), and others. Most of the GRB-devoted telescopes and observatories were obviously triggered, many of them with severe problems from detector dead time, pileup, and telemetry saturation: Swift/BAT (Dichiara et al 2022); MAXI (Negoro et al 2022); Fermi/LAT (Bissaldi et al 2022); AGILE (Piano et al 2022;Ursi et al 2022); INTEGRAL (Gotz et al 2022); Konus-Wind (Frederiks et al 2022); Insight-HMXT (Tan et al 2022); STPSat-6/SIRI (Mitchell et al 2022); GECAM (Liu et al 2022); SRG/ART-XC (Lapshov et al 2022); and GRBAlpha (Ripa et al 2022)).…”