BATSE All-Sky Search for Transient Gamma-Ray Lines between 300 and 550 keV

We present an all-sky search for bright, transient emission lines from 300 to 550 keV in more than two years (1993 December and 1996 March) of data from the Burst And Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory. Our approach is sensitive only to events with durations from 0.5-3.0 days. The results show that the gamma-ray sky is very "quiet" in these two years, which is consistent with an earlier search using BATSE data from 1991 to 1993. No transients are observed in the search, and our 3 σ upper limits are significantly below the fluxes of the two most significant events previously reported from Nova Muscae and 1E 1740.7-2942 by SIGMA. The disagreement between the BATSE data sets and those of SIGMA are quantitatively discussed.

[1]  Gerald J. Fishman,et al.  All-Sky Search for Transient Sources Near 0.5 MeV with the Burst and Transient Source Experiment (BATSE) , 1996 .

[2]  J. Bally,et al.  Is the Galactic Centre gamma-ray source 1E1740.7 – 2942 accreting from a molecular cloud? , 1991, Nature.

[3]  M. Niel,et al.  DETECTION OF A FEATURE AT 0.44 MEV IN THE CRAB PULSAR SPECTRUM WITH FIGARO-II - A REDSHIFTED POSITRON-ANNIHILATION LINE , 1991 .

[4]  H. Murakami,et al.  A Balloon Investigation of Galactic ?-ray Lines with a High Resolution Ge(Li) Spectrometer , 1979 .

[5]  C. A. Ayre,et al.  Gamma-ray line features from the Crab Nebula in the energy range 50–2000 keV , 1983 .

[6]  N. Khavenson,et al.  X-ray nova in Musca (GRS 1124 - 68) - Hard X-ray source with narrow annihilation line , 1992 .

[7]  M. Leventhal,et al.  A search for gamma-ray lines from Nova Cygni 1975, Nova Serpentis 1970, and the Crab Nebula , 1977 .

[8]  R. Misra,et al.  Formation of a Jet in the Galactic Center Black Hole Candidate 1E 1740.7-2942 , 1993 .

[9]  R. Ramaty,et al.  On the origin of variable 511 keV line emission from the Galactic center region , 1992 .

[10]  M. Livio,et al.  The Dual Nature of Hard X-Ray Outbursts from the Superluminal X-Ray Transient Source GRO J1655–40 , 1996, astro-ph/9610212.

[11]  P. Durouchoux,et al.  Gamma-ray line astrophysics , 1991 .

[12]  N. Khavenson,et al.  SIGMA/GRANAT soft gamma-ray observations of the X-ray nova in Musca : discovery of positron annihilation emission line , 1992 .

[13]  E. Costa,et al.  Observation of the Crab pulsar, PSR 0531 + 21, at 0. 2-6. 0 MeV with the Figaro II experiment , 1990 .