A cumulative search for hard X/γ-ray emission associated with fast radio bursts in Fermi/GBM data
Journal
Date Issued
2019
Author(s)
Martone, R.
•
Guidorzi, C.
•
Margutti, R.
•
•
•
Frontera, F.
•
•
•
Abstract
Context. Fast radio bursts (FRBs) are millisecond-long bursts uniquely detected at radio frequencies. FRB 131104 is the only case for which a γ-ray transient positionally and temporally consistent was claimed. This high-energy transient had a duration of ∼400 s and a 15-150 keV fluence Sγ ∼ 4 × 10-6 erg 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-variable Fermi/GBM instrumental background on a time interval comparable to the duration of the proposed γ-ray counterpart of FRB 131104. A possible γ-ray signal is then constrained considering sample average lightcurves.
Results: We constrain the fluence of the possible γ-ray signal in the 8-1000 keV band down to 6.4 × 10-7 (7.1 × 10-8) erg cm-2 for a 200-s (1-s) integration time. Furthermore, we found the radio-to-gamma fluence ratio to be η > 108 Jy ms erg-1 cm2.
Conclusions: Our fluence limits exclude ∼94% of Fermi/GBM detected long gamma-ray bursts and ∼96% of Fermi/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 a γ-ray counterpart as fluent as the one possibly associated with FRB 131104 to be a common feature of FRBs.
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-variable Fermi/GBM instrumental background on a time interval comparable to the duration of the proposed γ-ray counterpart of FRB 131104. A possible γ-ray signal is then constrained considering sample average lightcurves.
Results: We constrain the fluence of the possible γ-ray signal in the 8-1000 keV band down to 6.4 × 10-7 (7.1 × 10-8) erg cm-2 for a 200-s (1-s) integration time. Furthermore, we found the radio-to-gamma fluence ratio to be η > 108 Jy ms erg-1 cm2.
Conclusions: Our fluence limits exclude ∼94% of Fermi/GBM detected long gamma-ray bursts and ∼96% of Fermi/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 a γ-ray counterpart as fluent as the one possibly associated with FRB 131104 to be a common feature of FRBs.
Volume
631
Start page
A62
Issn Identifier
0004-6361
Ads BibCode
2019A&A...631A..62M
Rights
open.access
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