2004/02/25 by S. E. Shaw, M. J. Westmore, A. B. Hill +6 · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Gamma-ray bursts and supernovae #Radiation Detection and Scintillator Technologies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20034026
published as Astron.Astrophys. 418 (2004) 1187-1200 · 16 pages, 10 figures, accepted for publication in Astronomy and Astrophysics. Note: This pre-print contains lower resolution figures than the accepted paper
arxiv created 2004/02/25 · openalex publication_date 2004/04/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The BATSE mission aboard CGRO monitored the whole sky in the 20 keV-1 MeV energy band continuously from April 1991 until June 2000. Although BATSE had very poor intrinsic angular resolution, the data can be used to survey the entire soft gamma-ray sky with < angular resolution and ~mCrab sensitivity by using the Earth occultation method. This method determines flux by measuring the step in the count rate profile in each BATSE detector as a source rises above or sets below the Earth's limb. A maximum likelihood imaging technique can then be used to build up all-sky maps from the images of the Earth's limb produced by occulting sources. However, since the Earth seen from BATSE has a radius of ~70°, the limb images that intersect at the positions of bright point sources have a significant effect over the area of the all-sky map. A method for performing image cleaning on likelihood data has also been developed and is used to effectively remove artefacts from the all-sky maps. This paper describes the “LIMBO” imaging technique and presents preliminary all-sky maps of 25-160 keV emission, the first to be made since the HEAO1-A4 mission of 1978-79.