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BATSE observations of gamma-ray burst spectra. I - Spectral diversity
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Gamma‑ray burst spectra observed by BATSE are well described at low energies by a power‑law with an exponential cutoff and at high energies by a steeper power‑law, but the spectral shape varies among bursts. The study aimed to analyze the time‑averaged spectra of GRBs recorded by BATSE’s spectroscopy detectors. Spectral fitting was performed using complete models that include both low‑energy power‑law and high‑energy tail components, emphasizing the need for full descriptions even when partial models appear statistically adequate. The spectral parameters α, β, and the break energy E₀ varied widely across bursts, with E₀.
view Abstract Citations (1971) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS BATSE Observations of Gamma-Ray Burst Spectra. I. Spectral Diversity Band, D. ; Matteson, J. ; Ford, L. ; Schaefer, B. ; Palmer, D. ; Teegarden, B. ; Cline, T. ; Briggs, M. ; Paciesas, W. ; Pendleton, G. ; Fishman, G. ; Kouveliotou, C. ; Meegan, C. ; Wilson, R. ; Lestrade, P. Abstract We studied the time-averaged gamma-ray burst spectra accumulated by the spectroscopy detectors of the Burst and Transient Source Experiment (BATSE). The spectra are described well at low energy by a power-law continuum with an exponential cutoff N_E_(E) is proportional to Ealpha^ exp (- E/E_0_), and by a steeper power law, N_E_(E) is proportional to Ebeta^ with α > β at high energy. However, the spectral parameters α, β, and E_0_ vary from burst to burst with no universal values. The break in the spectrum, E_0_, ranges from below 100 keV to more than 1 MeV, but peaks below 200 keV with only a small fraction of the spectra breaking above 400 keV. Consequently, it is unlikely that a majority of the burst spectra are shaped directly by pair processes, unless bursts originate from a broad redshift range. We find that the correlations among burst parameters do not fulfill the predictions of the cosmological models of burst origin, but our burst sample may not be appropriate for such a test. No correlations with burst morphology or the spatial distribution were found. We also studied the process of fitting the BATSE spectral data. For example, we demonstrate the importance of using a complete spectral description even if a partial description (e.g., a model without a high-energy tail) is statistically satisfactory. Publication: The Astrophysical Journal Pub Date: August 1993 DOI: 10.1086/172995 Bibcode: 1993ApJ...413..281B Keywords: Galactic Halos; Gamma Ray Bursts; Gamma Ray Spectra; Statistical Analysis; Radiation Distribution; Transient Response; Space Radiation; GAMMA RAYS: BURSTS; RADIATION MECHANISMS: MISCELLANEOUS full text sources ADS | data products SIMBAD (54) NED (38) HEASARC (1) Related Materials (3) Part 2: 1995ApJ...439..307F Part 3: 1996ApJ...473..310P Part 4: 1998ApJ...496..849P