1999/12/01 by A. Mészáros, A. Meszaros, Z. Bagoly +4 · 2 citations
Mathematics · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Scientific Research and Discoveries #Statistical and numerical algorithms #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9912037
6 pages. Astronomy and Astrophysics, accepted for publication
arxiv created 1999/12/01 · openalex publication_date 1999/12/01 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
This articles is concerned primarily with the intrinsic anisotropy in the\nangular distribution of 2281 gamma-ray bursts (GRBs) collected in Current BATSE\nGamma-Ray Burst Catalog until the end of year 1998, and, second, with intrinsic\nanisotropies of three subclasses ("short", "intermediate", "long") of GRBs.\nTesting based on spherical harmonics of each class, in equatorial coordinates,\nis presented. Because the sky exposure function of BATSE instrument is not\ndependent on the right ascension \α, any non-zero spherical harmonic\nproportional either to Pnm(\sin \δ) \sin m \α or to Pnm(\sin\n\δ) \cos m\α with m \≠ 0 (\δ is the declination),\nimmediately indicates an intrinsic non-zero term. It is a somewhat surprising\nresult that the "intermediate" subclass shows an intrinsic anisotropy at the\n97 % significance level caused by the high non-zero P31(\sin \δ) \sin\nm \α harmonic. The remaining two subclasses, and the full sample of GRBs,\nremain isotropic.\n