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Soft Gamma-Ray Bursts in the BATSE data

Ya. Tikhomirova·B. Stern·A. Kozyreva·J. Poutanen
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Abstract

We performed the scan of the BATSE DISCLA records inspecting 25-50 keV range to pick up soft GRBs. We applied the same technique as in our previous (Stern et al. 2001) scan in the 50-300 keV range. We scanned about 1.8 year of the data and found 30 new gamma-ray burst (GRB)s. The total number of soft GRBs in the BATSE data, with the count rate in the 25-50 keV range higher than in the 50-300 keV range, is only 4%. There are about two extremely soft events per year which are invisible about 50 keV and which could constitute a new class of events separate from the GRB phenomenon. We also show that X-ray flashes (XRFs) detected by BeppoSAX have a hardness ratio very similar to that of normal GRBs, supporting a view that XRFs and GRBs are a single phenomenon with a wide spectral variety.

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Ya. Tikhomirova, B. Stern, A. Kozyreva, J. Poutanen. 2005-05-24. Soft Gamma-Ray Bursts in the BATSE data. https://arxiv.org/abs/astro-ph/0505490

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