Soft Gamma-Ray Bursts in the BATSE data
/ Authors
/ Abstract
W e perform ed the scan ofthe BATSE D ISCLA records inspecting 25-50 keV range to pick up softG RBs.W e applied the sam e technique asin ourprevious(Stern etal.2001)1 scan in the 50-300 keV range. W e scanned about1.8 yearofthe data and found 30 new gam m a-ray burst (G RB)s. The totalnum ber ofsoft G RBs 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 extrem ely soft events per year which are invisible about 50 keV and which could constitute a new class ofeventsseparate from the G RB phenom enon. W e also show thatX -ray (cid:13)ashes (X RFs) detected by BeppoSA X have a hardness ratio very sim ilar to that ofnorm alG RBs, supporting a view thatX RFsand G RBsarea singlephenom enon with a widespectralvariety.