{
  "bibcode": "2013GCN.14503....1A",
  "body": "L. Amati (INAF - IASF Bologna, Italy), S. Dichiara, F. Frontera, C. \nGuidorzi (University of Ferrara, Italy), report:\n\nBased on the preliminary values of fluence and spectral parameters \nreported by the Fermi/GBM (Kienlin et al., GCN 14473) and Konus-Wind \n(Golenetskii et al., GCN 14487) teams, and by assuming a redshift of 0.34 \n(Levan et al., CGN 14455; Flores et al., GCN 14491) and a standard \nLambda_CDM cosmology with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_Lambda \n= 0.73, we estimate for GRB 130427A an intrinsic spectral peak energy Ep,i \nof 1250+/-150 keV and an isotropic-equivalent radiated energy of \n(1.05+/-0.15)x10^54 erg (1-10000 keV cosmological rest-frame).\n\nThese values are fully consistent with the best-fit power-law of the \nEp,i-Eiso correlation holding for all long-bright cosmological GRBs (as \ndetermined, e.g., by Amati et al. 2009, A&A 508, 173). This is further \nevidence that the prompt emission properties of GRB 130427A, the most \nenergetic GRB detected at z < 1, are the same as those of very bright, \nhigh-redshift events. Hence, its relatively low redshift makes it a unique \ncase for investigating wether this class of events is associated to SNe \nwith properties similar to those associated to \"local\" sub-luminous GRBs.",
  "circularId": 14503,
  "createdOn": 1367255375000,
  "email": "amati@iasfbo.inaf.it",
  "subject": "GRB 130427A in the Ep,i - Eiso plane",
  "submitter": "Lorenzo Amati at INAF-IASF/Bologna  <amati@iasfbo.inaf.it>",
  "eventId": "GRB 130427A"
}