Explaining the statistical properties of Fast Radio Bursts with suppressed low-frequency emission

Abstract

The possibility of Fast Radio Burst (FRB) emission being suppressed at low frequencies, resulting in a cutoff of the average rest-frame spectrum, has been raised as an explanation for the lack of detections at meter wavelengths. We examine propagation effects that could cause this suppression, and find that a low-frequency spectral cutoff may be generic regardless of the specific FRB emission mechanism. We then illustrate the effects of a low-frequency spectral cutoff on the statistics of FRBs, given a cosmological source population. The observed FRB rate peaks at a specific frequency under a variety of assumptions. Observations at lower frequencies are more sensitive to high-redshift events than observations above the maximal-rate frequency, and therefore result in more sharply broken fluence distributions. Our results suggest that the absence of low-frequency FRBs, and the differences between the Parkes and the Australian Square Kilometre Array (ASKAP) FRB samples, can be fully explained by suppressed low-frequency FRB emission.

12 pages, 4 figures, submitted to AAS Journals

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Cited by in corpus (14)

• Fast Radio Bursts
• CHIME/FRB Detection of the Original Repeating Fast Radio Burst Source FRB 121102
• The lowest frequency Fast Radio Bursts: Sardinia Radio Telescope detection of the periodic FRB 180916 at 328 MHz
• Five new real-time detections of Fast Radio Bursts with UTMOST
• Fast Radio Burst dispersion measures and rotation measures and the origin of intergalactic magnetic fields
• Multiwavelength Radio Observations of Two Repeating Fast Radio Burst Sources: FRB 121102 and FRB 180916.J0158+65
• Synthesizing the intrinsic FRB population using frbpoppy
• First Discovery of a Fast Radio Burst at 350 MHz by the GBNCC Survey
• Imprint of local environment on fast radio burst observations
• Limits on Absorption from a 332-MHz survey for Fast Radio Bursts
• The Low Frequency Perspective on Fast Radio Bursts
• A targeted search for repeating fast radio bursts with the MWA
• Constraining the Fast Radio Burst (FRB) properties using the joint distributions of dispersion measure and fluence of the events detected at Parkes, ASKAP, CHIME and UTMOST
• A Multi-Mechanism Hybrid Model of Peaked-Spectrum Radio Sources