2024/10/08 by Subba, Nirpat, Subba, Nishika, Paul, Jyoti +2 · 1 citation
#Data Analysis #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph) #Statistics and Probability (physics.data-an)
paper · doi:10.48550/arxiv.2410.06201
This study investigates the timing and spectral characteristics of X-ray bursts from the neutron star system EXO 0748-676 using the NuSTAR observatory's FPMA and FPMB instruments in the 3-79 keV range. We identify Type I X-ray bursts driven by thermonuclear explosions on the neutron star's surface, notably a significant burst at \(X = 18,479.97\), indicating rapid energy release, followed by a recoil burst at \(X = 19,463.97\), reflecting stabilization. The correlation between burst timing and the neutron star's optical period suggests modulation by its rotation and periodic accretion dynamics. Spectral modeling reveals a photon index of \( Γ= 1.24 ± 0.014 \) and a cutoff energy of \( EC = 36.20 ± 1.04 keV \), indicating a hot corona around the neutron star. The measured flux of approximately \( (381.17 ± 0.014) × 10-12 erg cm-2 s-1 \) underscores the dynamic nature of accretion-driven systems. Calculated luminosities derived from distance estimates range from \( (3.86 ± 0.239) × 1036 erg/s \) to \( (2.3 ± 0.177) × 1036 erg/s \). Comparative analysis with prior observations from the IBIS/ISGRI instrument on the INTEGRAL satellite shows variability in emission characteristics, including softer photon indices and higher cutoff energies in 2003 and 2004. Our examination of smaller energy gaps (3-7 keV, 7-12 keV, etc.) reveals energy-dependent behavior in burst characteristics, enhancing our understanding of nuclear burning phases. Overall, these findings validate models describing Type I X-ray bursts and lay the groundwork for future investigations into similar astrophysical systems and stellar evolution processes in extreme environments.