Anton Chernenko (Space Research Institute (Moscow))
We propose a general method for analysis of time resolved gamma-ray spectra of astrophyscial transients. Instead of parameterizing individual spectra and analyzing spectral evolution of a transient in terms of numerous individual spectral fit parameters we define a spectral evolution model with a set of constant global parameters and just a few (N=1-2) time dependent variables (e.g. instant flux and time since the onset of the trnsient). This approach allows one to determine dimension (N) of the evolution and supplied global parameters for statistical studies of the source population.
Thus far a particular kind of a global fit analysis has been successfully used for revealing spectral components in cosmic gamma-ray bursts. In this paper we discuss other types spectral evolution models, optimal algorithms of multi-dimentional non-linear iterative optimization inherent in this method, determination of optimal temporal resolution permitted at a given S/N ratio, and M/C methods of estimation of global parameters' errors.