{\tt RapidGBM}: An Efficient Tool for Fermi-GBM Visibility Checking and Data Analysis with a Case Study of EP240617a

TL;DR

RapidGBM is a lightweight, web-based tool that enables rapid visibility checks and basic data analysis for Fermi-GBM transients, demonstrated through a case study of an X-ray transient, aiding quick classification and follow-up planning.

Contribution

The paper introduces RapidGBM, a novel, efficient tool for Fermi-GBM data analysis that operates with historical pointing files for real-time transient visibility and spectral analysis.

Findings

Successfully applied to classify EP240617a as an X-ray-rich gamma-ray burst.

Demonstrated rapid workflow from visibility check to spectral analysis.

Confirmed the feasibility of using historical pointing files for quick data analysis.

Abstract

We have developed a lightweight tool, {\tt RapidGBM}, featuring a web-based interface and capabilities of rapid calculation of Fermi Gamma-ray Burst Monitor (GBM) visibilities and performance of basic data analysis. It has two key features: (1) it can immediately check the visibility of Fermi-GBM for new transients, and (2) it can check the light curve and perform spectral analysis after the hourly Time-Tagger Event data are released. The visibility check and the response matrix generation required for spectral analysis can be achieved through the historical pointing file after the orbit calculation, even when the real-time pointing file is not yet available. As a case study, we apply the tool to EP240617a, an X-ray transient triggered by Einstein Probe (EP). We demonstrate the workflow of visibility checking, data processing, and spectral analysis for this event. The results suggest that EP240617a can be classified as an X-ray-rich gamma-ray burst (XRR) and confirm the feasibility of using historical pointing files for rapid analysis. Further, we discuss possible physical interpretations of such events, including implications for jet launching and progenitor scenarios. Therefore, {\tt RapidGBM} is expected to assist EP Transient Advocates, Space-based multiband astronomical Variable Objects Monitor burst advocates, and other members of the community in cross checking high-energy transients. Based on prompt emission parameter relations (e.g. $E_{\rm p}$-$E_{\gamma,\rm iso}$), it can also help identify peculiar GRBs (e.g. long-short burst, magnetar giant flare, etc.) and provide useful references (e.g. more accurate $T_0$) for scheduling follow-up observations.