{
  "bibcode": "2007GCN..6017....1A",
  "body": "L. Amati (INAF/IASF Bologna), F. Frontera (Univ. Ferrara and INAF/IASF \nBologna), C. Guidorzi (Univ. Milano Bicocca and INAF/OAB), E. Montanari \n(Univ. Ferrara and ITA \"Calvi\") report:\n\n\"Based on the correlation between power-law photon index and peak energy \nof GRB spectra measured by Swift/BAT in 15-150 keV (Zhang et al. 2006, \nastro-ph/0612238, and Sakamoto et al., ApJ, submitted), the photon index \nof 1.57+/-0.12 measured by BAT for GRB 070110 (Cummings et al, GCN 6007) \ncorresponds to a peak energy Ep of ~110+/-50 keV. From this spectral \ninformation and the reported 15-150 keV fluence of (1.6+/-0.1)x10^-6 \nerg/cm2 (GCN 6007), by assuming a Band spectral shape and by taking into \naccount the redshift of 2.352 (Jaunsen et al., GCN 6010), it is then \npossible to estimate the values of the intrinsic peak energy, Ep,i ~ \n370+/-170 keV, and of the isotropic equivalent radiated energy in the \n1-10000 keV cosmological rest frame, Eiso ~ (5.5+/1.5)x10^52 erg (the \nuncertainties on Ep,i and Eiso take approximately into account the \nmeasurements errors, the scatter of the photon index - peak energy \ncorrelation and the dependence of Eiso on the values assumed for alpha and \nbeta in the Band spectral model).\n\nThese values are consistent within 2 sigma with the Ep,i-Eiso correlation.\n\nIf, conservatively, we assume a Band model with alpha equal to the power-law \nspectral index measured by BAT and beta = -2.3, we find that GRB 070110 is \nconsistent with the Ep,i-Eiso correlation within 2 sigma for a measured Ep up \nto ~170 keV (E0 ~400 keV), and within 3 sigma for a measured Ep up to ~280 keV \n(E0 ~650 keV). These values of E0 are well above the upper bound of the BAT \nenergy band used for spectral analysis (150 keV).\n\nThus, we conclude that, despite the very peculiar behaviour shown by its \nX-ray afterglow after ~20 ks from the burst onset (Krimm et al., \nGCN_Report 26.2), GRB 070110 seems to be a common long event from the \npoint of its position in the Ep,i-Eiso plane. This, together with the \nstandard behaviour of the early afterglow light curve (steep decay, flat \ndecay) could indicate that the emission mechanisms / environment \noriginating the prompt emission are not necessarily linked to those \nproducing the LATE afterglow emission.\"\n\nThis message may be cited.",
  "circularId": 6017,
  "createdOn": 1168887451000,
  "email": "amati@iasfbo.inaf.it",
  "subject": "GRB 070110: Ep,i - Eiso correlation",
  "submitter": "Lorenzo Amati at INAF-IASF/Bologna  <amati@iasfbo.inaf.it>",
  "eventId": "GRB 070110"
}