Inferring the Energy and Distance Distributions of Fast Radio Bursts Using the First CHIME/FRB Catalog

Abstract

Fast radio bursts (FRBs) are brief, energetic, typically extragalactic flashes of radio emission whose progenitors are largely unknown. Although studying the FRB population is essential for understanding how these astrophysical phenomena occur, such studies have been difficult to conduct without large numbers of FRBs and characterizable observational biases. Using the recently released catalog of 536 FRBs published by the Canadian Hydrogen Intensity Mapping Experiment/Fast Radio Burst (CHIME/FRB) collaboration, we present a study of the FRB population that also calibrates for selection effects. Assuming a Schechter function, we infer a characteristic energy cut-off of E char = 2.38 − 1.64 + 5.35 × 10 41 erg and a differential power-law index of γ = − 1.3 − 0.4 + 0.7 . Simultaneously, we infer a volumetric rate of [ 7.3 − 3.8 + 8.8 (stat.) − 1.8 + 2.0 ( sys . ) ] × 10 4 Gpc−3 yr−1 above a pivot energy of 1039 erg and below a scattering timescale of 10 ms at 600 MHz, and find we cannot significantly constrain the cosmic evolution of the FRB population with star-formation rate. Modeling the host’s dispersion measure (DM) contribution as a log-normal distribution and assuming a total Galactic contribution of 80 pc cm−3, we find a median value of DM host = 84 − 49 + 69 pc cm−3, comparable with values typically used in the literature. Proposed models for FRB progenitors should be consistent with the energetics and abundances of the full FRB population predicted by our results. Finally, we infer the redshift distribution of FRBs detected with CHIME, which will be tested with the localizations and redshifts enabled by the upcoming CHIME/FRB Outriggers project.

Search for Gravitational Waves Associated with Fast Radio Bursts Detected by CHIME/FRB during the LIGO–Virgo Observing Run O3a

“…CHIME/FRB is deploying a set of Outrigger telescopes located at sufficient distances to allow autonomous very-longbaseline interferometry on CHIME/FRB detected bursts (Cassanelli et al 2022;Mena-Parra et al 2022). This development promises subarcsecond localizations on hundreds of FRBs per year allowing host galaxy identification and redshift determination through optical follow-ups or through cross matching of positional data with photometric galaxy surveys (Shin et al 2023). The resulting sample of FRBs at low redshift will be a significant development for GW detection networks, particularly as the sensitive volume increases with future observation runs and should allow targeted searches to obtain statistical evidence toward supporting or ruling out GW-FRB associations.…”

An Injection System for the CHIME/FRB Experiment

“…3. There is an absence of a strong selection against high DM events (Figure 9) suggesting that the dearth of high DM events in Catalog 1 is real and could arise from a DMfluence correlation (Shin et al 2022).…”

CHIME/FRB Discovery of 25 Repeating Fast Radio Burst Sources

“…The trends are similar regardless of the S/N threshold and the use of the NE2001 or the YMW16 model for the estimation of the eDM. Shin et al (2023) used a detailed population synthesis to infer a volumetric rate of of 7.3 × 10 4 bursts Gpc −3 yr −1 above a pivot energy of 10 39 erg and below a scattering timescale of 10 ms at 600 MHz based on FRBs in CHIME/FRB's first catalog. Based on the observed f rep in CHIME/FRB, the rate of active repeating sources can only be a few percent of that rate.…”

“…Apart from separate volumetric rates, it needs to be carefully considered whether they share other population model parameters, such as those describing their energy function, evolution through cosmic time, and spectral properties. Shin et al (2023) fit an energy function and volumetric rate to CHIME/FRB's first catalog. As ∼90% of FRBs in the first catalog are one-off events, it is likely that those measurements could be used well to model one-off events.…”