A Low-latency Pipeline for GRB Light Curve and Spectrum using Fermi/GBM Near Real-time Data

TL;DR

This paper presents a low-latency pipeline that rapidly analyzes Fermi/GBM data to determine GRB properties within 20 minutes, aiding real-time astronomical follow-ups and multi-messenger observations.

Contribution

The authors developed a near real-time pipeline for GRB analysis that significantly reduces latency and has been successfully integrated into follow-up observations.

Findings

Achieves parameter estimation within ~20 minutes post-trigger

T90 and fluence are consistent with catalog results for 90% of GRBs

Enabled timely follow-up observations for GW-associated GRBs

Abstract

Rapid response and short time latency are very important for Time Domain Astronomy, such as the observations of Gamma-ray Bursts (GRBs) and electromagnetic (EM) counterparts of gravitational waves (GWs). Based on the near real-time Fermi/GBM data, we developed a low-latency pipeline to automatically calculate the temporal and spectral properties of GRBs. With this pipeline, some important parameters can be obtained, such as T90 and fluence, within ~20 minutes after the GRB trigger. For ~90% GRBs, T90 and fluence are consistent with the GBM catalog results within 2 sigma errors. This pipeline has been used by the Gamma-ray Bursts Polarimeter (POLAR) and the Insight Hard X-ray Modulation Telescope (Insight-HXMT) to follow up the bursts of interest. For GRB 170817A, the first EM counterpart of GW events detected by Fermi/GBM and INTEGRAL/SPI-ACS, the pipeline gave T90 and spectral information in 21 minutes after the GBM trigger, providing important information for POLAR and Insight-HXMT observations.