Fermi Gamma-ray Space Telescope

Non-parametric dead time influence estimation for TGF

Alexei Pozanenko
P. Minaev V. Vybornov

Abstract:

A technique of alignment and stacking of TGFs was developed. Due to small number of photons registered from each TGF event (as low as 10) the special technique of time profiles alignment is necessary. We investigate robustness of the technique using Monte-Carlo simulations. We also revise the TGF RHESSI catalog [Grefenstette, 2009] extending data retrieved time interval of data retrieved . Using the technique we construct a stacked profile of all TGFs on the time scale +/- 1 s against TGF peak. The stacked profile is used for non-parametric dead time estimation of TGF registered by RHESSI as well as for investigation of general properties of TGF time profile. It is found that a lower limit of dead time effects for bright TGFs registered by RHESSI experiment is not less than 60 percent. We found that stacked light curve of all TGFs is asymmetric and consists at least of two components. We also discuss application of the developed technique to the TGFs registered by GBM/Fermi.