A cosmographic calibration of the e p,i-Eiso(Amati) relation for GRBs

Abstract

Aims. The Amati relation, which connects the isotropic energy emitted and the rest-frame peak energy of the νFν spectra of GRBs, is cosmology-dependent, so we need a method to obtain an independent calibration of the Amati relation. Methods. Using the Union Supernovae Ia catalog, we obtain a cosmographic luminosity distance in the y-redshift and verify that this parameterization very well approximates the fiducial standard cosmological model ΔCDM. Using this cosmographic luminosity distance dl, we compute the Amati relation considering this cosmology-independent definition of dl. Results. The cosmographic Amati relation we obtain agrees in the errors with other cosmology-independent calibrations proposed in the literature. © 2010 ESO.