Estudio de la variabilidad temporal de la emisión gamma del remanente de supernova W28 con el Telescopio Espacial Fermi

Abstract

In this work we study the galactic supernova remnant W28 to characterize its spectrum and temporal evolution, in order to investigate the interaction of the star with molecular clusters and determine the dominant process in the generation of astrophysical photons. The Fermi-LAT detector, which is located within the Fermi-Gamma Space Telescope, has been used to analyze 10 years of data (04 - August - 2008 to 04 - August - 2018). Through the analysis of the light curves, the temporal dynamics of W28 have been characterized and two relevant periods of activity with significance of 8σ and 6σ respectively have been found. These results confirm the hypothesis of hadronic photoproduction from the consistency found in studies of molecular indicators. However, it is not possible to completely rule out the hypothesis of leptonic photoproduction, in particular at low energies <1GeV. On the other hand, three spectral models have been used to adjust the data of the source region: power law, cut power law and logarithmic parabola. The parameters obtained for PL and BPL are consistent with those found in the literature, however, the we could not establish the best model that fits the data properly due to lack of statistical evidence.