The First CHIME/FRB Fast Radio Burst Catalog

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.

The FRB 20121102A November rain in 2018 observed with the Arecibo Telescope

“…Observationally FRBs are divided into repeaters and FRBs that have so far only been detected once. Amiri et al (2021) found that these two populations indeed have different statistical properties with repeaters having narrower bandwidths and longer durations on average (Pleunis et al 2021). Moreover, the temporal downward drift in frequency of sub-bursts (Hessels et al 2019) -the so-called sadtrombone effect -is characteristic for repeaters, while being very rare in (apparent) non-repeaters.…”

“…Fast radio bursts (FRBs) are millisecond-duration flashes of radio waves that are of extragalactic origin (Lorimer et al 2007). The sources of FRBs and their emission mechanisms are still uncertain (see Petroff et al 2021;Lyubarsky 2021, for recent reviews), but growing numbers of FRBs (Amiri et al 2021) and localizations within host galaxies (e.g. Bannister et al 2019;Bhandari et al 2022) recently boosted our understanding of their statistical properties.…”

Comparison of the Parkes and FAST FRB DM Distribution

“…Whilst the CHIME collaboration recently published its first FRB catalogue (Amiri et al 2021), we note that the CHIME telescope has a very different frequency range to FAST and it is unclear whether these results would be scalable for a comparative analysis. Furthermore, CHIME has a significantly different and complicated beam-pattern that would need to be treated in such an analysis.…”

“…(ii) Searches may be biased against either low or high DM events (e.g., a deficit of low-DM FRBs may result from a bias against low-DM events due to RFI discrimination, -see, e.g., Amiri et al (2021) regarding bias against low DM events due to RFI).…”

Search for Coincident Gravitational Wave and Fast Radio Burst Events from 4-OGC and the First CHIME/FRB Catalog

“…The Canadian Hydrogen Intensity Mapping Experiment (CHIME) (Amiri et al 2018) has released the first CHIME/FRB catalog (Amiri et al 2021), reporting 536 events within one year of observation. For three months, from April 1 to July 1 in 2019, the gravitationalwave detectors Advanced LIGO/Virgo and CHIME were both observing, establishing the opportunity to search for coincident signals.…”