African Astronomical Society conference and General Assembly 2025 (AfAS-2025)

Implications of Joint Spectral Analysis of Gamma-Ray Bursts (GRBs) detected by Fermi Large Area Telescope and GRB Monitor on Phenomenological Correlations

Not scheduled

15m

Emperors Palace Hotel Casino Convention Resort

Poster

Speakers

Tamador Khalil Mansoor Aldowma (University of Johannesburg) Soebur Razzaque (University of Johannesburg)

Description

Gamma-ray bursts (GRBs) have emerged as powerful cosmological probes for measuring distances in the Universe. Numerous empirical correlations have been established, particularly about their energy properties. This work aims to enhance the precision of these correlations through joint spectral analysis, focusing on reducing uncertainties in both the spectral indices and the peak energy ($E_{\mathrm{p}\mathrm{e}\mathrm{a}\mathrm{k}}$) derived from spectral fitting. We extend previous studies using traditional and novel spectral models, utilizing a sample of 42 GRBs observed by Fermi(LAT, GBM), including LAT-LLE data. Our analysis compares results from joint fits (GBM-LAT-LLE) against those from GBM-only fits. The study focuses on fitting time-integrated $T_{90}$ and peak flux in the rest frame. Among the observable phenomenological correlations, we revisit the Amati and Yonetoku relations; Amati is the relation between the intrinsic peak energy ($E_{i,\mathrm{p}\mathrm{e}\mathrm{a}\mathrm{k}}$) of the spectrum to the total isotropic energy ($E_{\mathrm{i}\mathrm{s}\mathrm{o}}$) emitted during the burst duration ($T_{90}$), and the Yonetoku relation, correlating between the intrinsic peak energy ($E_{i,\mathrm{p}\mathrm{e}\mathrm{a}\mathrm{k}}$) with the isotropic luminosity ($L_{\mathrm{i}\mathrm{s}\mathrm{o}}$). Refining these correlations aims to deepen the understanding of GRB energetics and improve the precision of cosmological parameter constraints derived from GRB observations.