Fast radio bursts as synchrotron maser emission from decelerating relativistic blast waves
By B. Metzger, B. Margalit, L. Sironi. Monthly notices of the Royal Astronomical Society, 2019
328 citations recorded by the source corpus.
Fast radio bursts (FRBs) can arise from synchrotron maser emission at ultrarelativistic magnetized shocks, such as produced by flare ejecta from young magnetars. We combine particle-in-cell simulation results for the maser emission with the dynamics of self-similar shock deceleration, as commonly applied to gamma-ray bursts (GRBs), to explore the implications for FRBs. The upstream environment is a mildly relativistic baryon-loaded shell released following a previous flare, motivated by the high electron–ion injection rate $\dot{M} \sim 10^{19}\!-\!10^{21}$ g s−1 needed to power the persistent radio nebula coincident with the repeating burster FRB 121102 and its high rotation measure. The radio fluence peaks once the optical depth ahead of the shock to induced Compton scattering τc ≲ 3. Given intervals between major ion ejection events ΔT ∼ 105 s similar to the occurrence rate of the most powerful bursts from FRB 121102, we demonstrate the production of ∼0.1–10 GHz FRBs with isotropic radiated energies ∼1037–1040 erg and durations ∼0.1–10 ms for flare energies E ∼ 1043–1045 erg. Deceleration of the blast wave, and increasing transparency of the upstream medium, generates temporal decay of the peak frequency, similar to the observed downward frequency drift seen in FRB 121102 and FRB 180814.J0422+73. The delay ΔT ≳ 105 s between major ion-injection events needed to clear sufficiently low densities around the engine for FRB emission could explain prolonged ‘dark periods’ and clustered burst arrival times. Thermal electrons heated at the shock generate a short-lived ≲1 ms (1 s) synchrotron transient at gamma-ray (X-ray) energies, analogous to a scaled-down GRB afterglow.
Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/56f2fe904bf767de29b0f824fc6e3d8f5d523356
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Citations in the corpus
- Fast Radio Burst Morphology in the First CHIME/FRB Catalog (2021, unknown): “Some proposed models for FRBs predict narrowband emission: decelerating blast waves result in Δν/ν∼ 1 emission (Metzger et al. 2019), which is narrowband but still necessitates some external effect to produce the Δν/ν∼ 0.1 that is observed for repeater bursts.”
- Fast radio bursts at the dawn of the 2020s (2021, unknown): “In other models, the FRB is generated via synchrotron maser emission in the forward shock of a propagating flare from the magnetar as it collides with the surrounding medium at radial distances of J105 km (Metzger et al. 2019).”
- CHIME/FRB Discovery of Eight New Repeating Fast Radio Burst Sources (2019, methodology): “…unknown, though many different models have been proposed (see Platts et al. 2018; Petroff et al. 2019), ranging from synchrotron maser emission from young magnetars in supernova remnants (Lyubarsky 2014; Beloborodov 2017; Metzger et al. 2019) to cosmic string cusps (Brandenberger et al. 2017).”
- Blast Waves from Magnetar Flares and Fast Radio Bursts (2019, methodology): “Metzger et al. (2019) recently developed a detailed model for blast waves in such tails and suggested that their emission reproduces the observations of FRB121102.”
- Nine New Repeating Fast Radio Burst Sources from CHIME/FRB (2020, background): “A variant of this model (Metzger et al. 2019) has since been developed and found to be consistent with burst properties reported for the initial batch of CHIME repeaters (see Paper I).”
- Fast Radio Bursts from Magnetars Born in Binary Neutron Star Mergers and Accretion Induced Collapse (2019, background): “Although adopted for simplicity of presentation and analytic tractability, we note that such a toy model was shown to not be able to reproduce in detail both the RM and persistent radio luminosity of FRB121102 (Margalit & Metzger 2018).”
- A unified picture of Galactic and cosmological fast radio bursts (2020, background): “…ejecta from a neutron star (or black hole) dissipates its energy at large dis- tances by interacting with the circum-stellar medium (CSM) and the radio emission is generated by a maser process (Lyubarsky 2014; Waxman 2017; Beloborodov 2017, 2019; Metzger et al. 2019; Margalit et al. 2020).”
- A Nearby Repeating Fast Radio Burst in the Direction of M81 (2021, background): “For example, in the synchrotron maser model of Metzger et al. (2019), shockheated electrons gyrate to produce synchrotron radiation that sweeps through the γ-ray and X-ray bands and, in some cases, even extends to the optical band on subsecond timescales.”