Self-modulation of Fast Radio Bursts

Abstract

Fast Radio Bursts (FRBs) are extreme astrophysical phenomena entering the realm of non-linear optics, a field developed in laser physics. A classical non-linear effect is self-modulation. We examine the propagation of FRBs through the circumburst environment using the idealised setup of a monochromatic linearly-polarised GHz wave propagating through a uniform plasma slab of density $N$ at distance $R$ from the source. We find that self-modulation occurs if the slab is located within a critical radius $R_{\mathrm{crit}}\sim 10^{17}(N/10^2{\mathrm{cm}}^{-3})(L/10^{42}{\mathrm{erg}\mathrm{s}}^{-1})\mathrm{cm}$, where $L$ is the isotropic equivalent of the FRB luminosity. Self-modulation breaks the burst into pancakes transverse to the radial direction. When $R\lesssim R_{\mathrm{crit}}$, the transverse size of the pancakes is smaller than the Fresnel scale. The pancakes are strongly diffracted as the burst exits the slab, and interference between the pancakes produces a frequency modulation of the observed intensity with a sub-GHz bandwidth. When $R\sim R_{\mathrm{crit}}$, the transverse size of the pancakes becomes comparable with the Fresnel scale, and the effect of diffraction is weaker. The observed intensity is modulated on a timescale of ten microseconds, which corresponds to the radial width of the pancakes. Our results suggest that self-modulation may cause the temporal and frequency structure observed in FRBs.

arXiv commentaccepted for publication in MNRAS

References in corpus (31)

• A bright millisecond radio burst of extragalactic origin
• A Population of Fast Radio Bursts at Cosmological Distances
• A Repeating Fast Radio Burst
• The direct localization of a fast radio burst and its host
• Fast Radio Burst Discovered in the Arecibo Pulsar ALFA Survey
• An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102
• Fast Radio Bursts: An Extragalactic Enigma
• FRBCAT: The Fast Radio Burst Catalogue
• Fast radio bursts as synchrotron maser emission from decelerating relativistic blast waves
• CHIME/FRB Detection of Eight New Repeating Fast Radio Burst Sources
• The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales
• A flaring magnetar in FRB 121102?
• FRB 121102 Bursts Show Complex Time-Frequency Structure
• A Second Source of Repeating Fast Radio Bursts
• Five new Fast Radio Bursts from the HTRU high latitude survey: first evidence for two-component bursts
• Radio Emission Signatures in the Crab Pulsar
• Blast Waves from Magnetar Flares and Fast Radio Bursts
• Observations of Fast Radio Bursts at Frequencies down to 400 Megahertz
• FRB microstructure revealed by the real-time detection of FRB170827
• Spectropolarimetric analysis of FRB 181112 at microsecond resolution: Implications for Fast Radio Burst emission mechanism
• Physical Constraints On Fast Radio Burst
• Constraints on the Engines of Fast Radio Bursts
• The Crab Pulsar at Centimeter Wavelengths II: Single Pulses
• Five new real-time detections of Fast Radio Bursts with UTMOST
• Induced scattering of short radio pulses
• Radius-to-frequency mapping and FRB frequency drifts
• Fast radio bursts as strong waves interacting with ambient medium
• Imprint of local environment on fast radio burst observations
• Nonlinear optics in strongly magnetized pair plasma, with applications to FRBs
• Interaction of the electro-magnetic precursor from a relativistic shock with the upstream flow. I. Synchrotron absorption of strong electromagnetic waves
• Nonlinear scattering of Fast Radio Bursts

Cited by in corpus (18)

• The Physics of Fast Radio Bursts
• Periodic Fast Radio Bursts from Luminous X-ray Binaries
• Implications of a rapidly varying FRB in a globular cluster of M81
• Coherent Electromagnetic Emission from Relativistic Magnetized Shocks
• A burst storm from the repeating FRB 20200120E in an M81 globular cluster
• Linearly-polarized Coherent Emission from Relativistic Magnetized Ion-electron Shocks
• Saturation of the filamentation instability and dispersion measure of Fast Radio Bursts
• Filamentation of Fast Radio Bursts in magnetar winds
• Nonlinear electromagnetic-wave interactions in pair plasma: (I) Non-relativistic regime
• A Toy Model for the Time-Frequency Structure of Fast Radio Bursts: Implications for the CHIME Burst Dichotomy
• Constraining the FRB mechanism from scintillation in the host galaxy
• Propagation effects in the FRB 20121102A spectra
• Particle Acceleration by Pickup Process Upstream of Relativistic Shocks
• Kinetic Simulations of the Filamentation Instability in Pair Plasmas
• Highly polarised microstructure from the repeating FRB 20180916B
• A Practical Framework for Estimating the Repetition Likelihood of Fast Radio Bursts from Spectral Morphology
• Filamentation of the electromagnetic precursor in relativistic quasi-perpendicular electron-positron shocks
• Emission Mechanisms of Fast Radio Bursts