We present a sample composed of the 41 faintest X-ray afterglows of the population of long gamma-ray bursts (lGRBs) with known redshift. We study their intrinsic properties (spectral index, decay index, distance, luminosity, isotropic radiated energy, and peak energy) and their luminosity distribution functions to assess whether they belong to the same population as the brighter afterglow events. We find that these events belong to a population of nearby ones, different from the general population of lGRBs. In addition, these events are faint during their prompt phase, and include the few possible outliers of the Amati relation.
Bibliographical noteFunding Information:
This paper is under the auspices of the FIGARONet collaborative network, supported by the Agence Nationale de la Recherche, program ANR-14-CE33. We used the data supplied by the UK Swift Science Data Center at the University of Leicester. This work has been part of the H.D. PhD. thesis supported by the Erasmus Mundus Joint Doctorate Program by grant Number 2011-1640 from the EACEA of the European Commission. H.D. acknowledges financial support from Bilim Akademisi, The Science Academy, Turkey under the TÜBITAK-BAGEP program 1059B191500067. B.G. and N.B.O. acknowledge financial support of the NASA through the NASA Award NNX13AD28A and the NASA Award NNX15AP95A.
© 2017. The American Astronomical Society. All rights reserved..
- X-rays: general
- gamma-ray burst: general
- methods: data analysis