摘要：Context.Fast radio bursts (FRBs) are millisecond-long bursts uniquely detected at radio frequencies. FRB 131104 is the only case for which aγ-ray transient positionally and temporally consistent was claimed. This high-energy transient had a duration of ∼400 s and a 15–150 keV fluenceSγ ∼ 4 × 10−6erg cm−2. However, the association with the FRB is still debated.Aims.We aim at testing the systematic presence of an associated transient high-energy counterpart throughout a sample of the FRB population.Methods.We used an approach like that used in machine learning methodologies to accurately model the highly-variableFermi/GBM instrumental background on a time interval comparable to the duration of the proposedγ-ray counterpart of FRB 131104. A possibleγ-ray signal is then constrained considering sample average lightcurves.Results.We constrain the fluence of the possibleγ-ray signal in the 8–1000 keV band down to 6.4 × 10−7(7.1 × 10−8) erg cm−2for a 200-s (1-s) integration time. Furthermore, we found the radio-to-gamma fluence ratio to beη > 108Jy ms erg−1cm2.Conclusions.Our fluence limits exclude ∼94% ofFermi/GBM detected long gamma-ray bursts and ∼96% ofFermi/GBM detected short gamma-ray bursts. In addition, our limits on the radio-to-gamma fluence ratio point to a different emission mechanism from that of magnetar giant flares. Finally, we exclude aγ-ray counterpart as fluent as the one possibly associated with FRB 131104 to be a common feature of FRBs.
关键词：engamma rays: generalgamma-ray burst: generalradio continuum: general
