Classification of Fermi Gamma-RAY Bursts
  The Fermi GBM Catalog has been recently published. Previous classification
analyses of the BATSE, RHESSI, BeppoSAX, and Swift databases found three types
of gamma-ray bursts. Now we analyzed the GBM catalog to classify the GRBs. PCA
and Multiclustering analysis revealed three groups. Validation of these groups,
in terms of the observed variables, shows that one of the groups coincides with
the short GRBs. The other two groups split the long class into a bright and dim
part, as defined by the peak flux. Additional analysis is needed to determine
whether this splitting is only a mathematical byproduct of the analysis or has
some real physical meaning.
