Abstract
Abstract We present a catalog of 536 fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project between 400 and 800 MHz from 2018 July 25 to 2019 July 1, including 62 bursts from 18 previously reported repeating sources. The catalog represents the first large sample, including bursts from repeaters and nonrepeaters, observed in a single survey with uniform selection effects. This facilitates comparative and absolute studies of the FRB population. We show that repeaters and apparent nonrepeaters have sky locations and dispersion measures (DMs) that are consistent with being drawn from the same distribution. However, bursts from repeating sources differ from apparent nonrepeaters in intrinsic temporal width and spectral bandwidth. Through injection of simulated events into our detection pipeline, we perform an absolute calibration of selection effects to account for systematic biases. We find evidence for a population of FRBs—composing a large fraction of the overall population—with a scattering time at 600 MHz in excess of 10 ms, of which only a small fraction are observed by CHIME/FRB. We infer a power-law index for the cumulative fluence distribution of α = − 1.40 ± 0.11 ( stat. ) − 0.09 + 0.06 ( sys. ) , consistent with the −3/2 expectation for a nonevolving population in Euclidean space. We find that α is steeper for high-DM events and shallower for low-DM events, which is what would be expected when DM is correlated with distance. We infer a sky rate of [ 820 ± 60 ( stat. ) − 200 + 220 ( sys. ) ] / sky / day above a fluence of 5 Jy ms at 600 MHz, with a scattering time at 600 MHz under 10 ms and DM above 100 pc cm−3.
Highlights
The first Fast Radio Burst (FRB) was discovered nearly a decade and a half ago (Lorimer et al 2007), the nature of these sources remains a mystery
While this uncertainty treatment is most appropriate for pulsar-like spectra, we note that the true positions of the two localized repeaters, both emitting band-limited and morphologically complex bursts, are contained in the uncertainty regions of their respective Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB signal-to-noise ratio (SNR)-based localizations
We draw 5 × 106 FRBs and randomly assign them to the surviving sky locations. The properties of these FRBs are drawn from initial probability density functions Pinit(F ), Pinit(DM), Pinit(τ ), Pinit(w), and Pinit(γ, r) designed to both fully sample the range of observed properties and more densely sample parts of phase space populated by the catalog
Summary
The first Fast Radio Burst (FRB) was discovered nearly a decade and a half ago (Lorimer et al 2007), the nature of these sources remains a mystery. One Galactic magnetar has shown both repeated X-ray bursts and a radio burst of luminosity close to the FRB range (CHIME/FRB Collaboration et al 2020b; Bochenek et al 2020). This suggests that repeaters may be young, active magnetars, a scenario consistent with localizations of repeating FRBs to star-forming locations (Chatterjee et al 2017; Marcote et al 2020). A detailed study of large numbers of FRBs, in a single homogeneous survey with a well-measured instrument selection function, is desirable for many additional reasons.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
