Constraints on FRB emission in the aftermath of GRBs

The physical origin of Fast Radio Bursts (FRBs) is still unknown. Many models consider magnetars as possible FRB sources, supported by the observational association of FRBs with the galactic magnetar SGR 1935+2154. Magnetars are also thought to be the source of the power of a fraction of Gamma Ray Bursts (GRBs), opening the possibility that the two extreme phenomena have a common progenitor. In this talk we present a new, systematic search for GRB-FRB association, using the most updated catalog of FRBs observed with the Canadian Hydrogen Intensity Mapping Experiment (CHIME) instrument, and the sample of all GRBs detected by Swift so far. We also show, using a synthetic population of FRBs associated to Swift GRBs, how likely it is to have a joint detection with current and future radio facilities. With our analysis we only recovered two, low significant, possible GRB-FRB associations already reported in literature; however the absence of any unambiguous association so far between Swift GRBs and FRBs cannot exclude that the two populations are connected, given the characteristics of current GRB and FRB detectors. In the next decade, with new generations of GRB and FRB detectors there will be a higher probability to detect joint GRB-FRB events, if any. 558 High-energy emission in SGRs/AXPs Instituto Tecnológico de Aeronáutica 2 ICRANet 3 UTFPR In this work, we investigate the high-energy emission in SGRs/AXPs, neutron stars with extreme magnetic field, named magnetars. The observed high-energy emission in the X-rays and gammaray bands are explained. The outer gap accelerator model considers the generation of high-energy emission far away from the surface of the star in a combination of curvature radiation and inverse Compton scattering. The high-energy emission is constrained by employing the death-lines, the condition for pair-production and the generation of hard X and soft gamma rays. From the point of the death-lines and death-zones obtained here by the outer gap model the SGRs/AXPs should not emit hard X-rays, since they are below the death-line, in disagreement with the observations: SGRs/AXPs are characterized by short and intense burst in the hard X-rays (few hundred keV). The reason for the absence of hard X-Ray emission in the outer gap model, is the low magnetic field strength at the light cylinder, which is too far away from the star’s surface in comparison to millisecond γ-rays pulsars.