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.

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No Evidence for Galactic Latitude Dependence of the Fast Radio Burst Sky Distribution

The Astrophysical Journal ◽

10.3847/1538-4357/ac33ad ◽

2021 ◽

Vol 923 (1) ◽

pp. 2 ◽

Cited By ~ 1

Author(s):

A. Josephy ◽

P. Chawla ◽

A. P. Curtin ◽

V. M. Kaspi ◽

M. Bhardwaj ◽

...

Keyword(s):

Radio Burst ◽

Sensitivity Threshold ◽

Galactic Latitude ◽

Radio Bursts ◽

Intensity Mapping ◽

Latitude Dependence ◽

Kolmogorov Smirnov ◽

Coin Flipping ◽

Fast Radio Burst ◽

Anderson Darling

Abstract We investigate whether the sky rate of fast radio bursts (FRBs) depends on Galactic latitude using the first catalog of FRBs detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project. We first select CHIME/FRB events above a specified sensitivity threshold in consideration of the radiometer equation, and then we compare these detections with the expected cumulative time-weighted exposure using Anderson–Darling and Kolmogorov–Smirnov tests. These tests are consistent with the null hypothesis that FRBs are distributed without Galactic latitude dependence (p-values distributed from 0.05 to 0.99, depending on completeness threshold). Additionally, we compare rates in intermediate latitudes (∣b∣ < 15°) with high latitudes using a Bayesian framework, treating the question as a biased coin-flipping experiment–again for a range of completeness thresholds. In these tests the isotropic model is significantly favored (Bayes factors ranging from 3.3 to 14.2). Our results are consistent with FRBs originating from an isotropic population of extragalactic sources.

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GREENBURST: A commensal Fast Radio Burst search back-end for the Green Bank Telescope

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2019.26 ◽

2019 ◽

Vol 36 ◽

Cited By ~ 2

Author(s):

Mayuresh P. Surnis ◽

D. Agarwal ◽

D. R. Lorimer ◽

X. Pei ◽

G. Foster ◽

...

Keyword(s):

Radio Burst ◽

High Sensitivity ◽

Pixel Detector ◽

Search System ◽

Dispersion Measures ◽

Fast Radio Burst ◽

Radio Transients ◽

Green Bank Telescope ◽

Single Pixel ◽

Rotating Radio Transients

Abstract We describe the design and deployment of GREENBURST, a commensal Fast Radio Burst (FRB) search system at the Green Bank Telescope. GREENBURST uses the dedicated L-band receiver tap to search over the 960–1 920 MHz frequency range for pulses with dispersion measures out to $10^4\ \rm{pc\,cm}^{-3}$ . Due to its unique design, GREENBURST is capable of conducting searches for FRBs when the L-band receiver is not being used for scheduled observing. This makes it a sensitive single pixel detector capable of reaching deeper in the radio sky. While single pulses from Galactic pulsars and rotating radio transients will be detectable in our observations, and will form part of the database we archive, the primary goal is to detect and study FRBs. Based on recent determinations of the all-sky rate, we predict that the system will detect approximately one FRB for every 2–3 months of continuous operation. The high sensitivity of GREENBURST means that it will also be able to probe the slope of the FRB fluence distribution, which is currently uncertain in this observing band.

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First Discovery of New Pulsars and RRATs with CHIME/FRB

The Astrophysical Journal ◽

10.3847/1538-4357/ac1da6 ◽

2021 ◽

Vol 922 (1) ◽

pp. 43

Author(s):

D. C. Good ◽

B. C. Andersen ◽

P. Chawla ◽

K. Crowter ◽

F. Q. Dong ◽

...

Keyword(s):

Radio Burst ◽

Single Pulse ◽

Radio Sources ◽

Pulse Emission ◽

Intensity Mapping ◽

Fast Radio Burst ◽

Radio Transients ◽

Galactic Sources ◽

Rotating Radio Transients ◽

Galactic Radio

Abstract We report the discovery of seven new Galactic pulsars with the Canadian Hydrogen Intensity Mapping Experiment’s Fast Radio Burst (CHIME/FRB) backend. These sources were first identified via single pulses in CHIME/FRB, then followed up with CHIME/Pulsar. Four sources appear to be rotating radio transients, pulsar-like sources with occasional single-pulse emission with an underlying periodicity. Of those four sources, three have detected periods ranging from 220 ms to 2.726 s. Three sources have more persistent but still intermittent emission and are likely intermittent or nulling pulsars. We have determined phase-coherent timing solutions for the latter two. These seven sources are the first discovery of previously unknown Galactic sources with CHIME/FRB and highlight the potential of fast radio burst detection instruments to search for intermittent Galactic radio sources.

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The performance and calibration of the CRAFT fly’s eye fast radio burst survey

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2019.1 ◽

2019 ◽

Vol 36 ◽

Cited By ~ 11

Author(s):

C. W. James ◽

K. W. Bannister ◽

J.-P. Macquart ◽

R. D. Ekers ◽

S. Oslowski ◽

...

Keyword(s):

Radio Burst ◽

Phased Array ◽

Radio Frequency Interference ◽

Radio Bursts ◽

System Noise ◽

Fast Transients ◽

Fast Radio Burst ◽

Power Law Index ◽

Phased Array Feeds ◽

Best Fit

AbstractThe Commensal Real-time Australian Square Kilometre Array Pathfinder Fast Transients survey is the first extensive astronomical survey using phased array feeds. Since January 2017, it has been searching for fast radio bursts in fly’s eye mode. Here, we present a calculation of the sensitivity and total exposure of the survey that detected the first 20 of these bursts, using the pulsars B1641-45 and B0833-45 as calibrators. The beamshape, antenna-dependent system noise, and the effects of radio-frequency interference and fluctuations during commissioning are quantified. Effective survey exposures and sensitivities are calculated as a function of the source counts distribution. Statistical ‘stat’ and systematics ‘sys’ effects are treated separately. The implied fast radio burst rate is significantly lower than the 37 sky−1 day−1 calculated using nominal exposures and sensitivities for this same sample by Shannon et al. (2018). At the Euclidean (best-fit) power-law index of −1.5 (−2.2), the rate is $12.7_{-2.2}^{+3.3}$ (sys) ± 3.6 (stat) sky−1 day−1 ( $20.7_{-1.7}^{+2.1}$ (sys) ± 2.8 (stat) sky−1 day−1) above a threshold of 56.6 ± 6.6(sys) Jy ms (40.4 ± 1.2(sys) Jy ms). This strongly suggests that these calculations be performed for other FRB-hunting experiments, allowing meaningful comparisons to be made between them.

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Dispersion Measures of Fast Radio Burst Host Galaxies Derived from IllustrisTNG Simulation

The Astrophysical Journal ◽

10.3847/1538-4357/abaa4a ◽

2020 ◽

Vol 900 (2) ◽

pp. 170 ◽

Cited By ~ 1

Author(s):

G. Q. Zhang ◽

Hai Yu ◽

J. H. He ◽

F. Y. Wang

Keyword(s):

Radio Burst ◽

Host Galaxies ◽

Dispersion Measures ◽

Fast Radio Burst

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INFERENCES FROM THE DISTRIBUTIONS OF FAST RADIO BURST PULSE WIDTHS, DISPERSION MEASURES, AND FLUENCES

The Astrophysical Journal ◽

10.3847/0004-637x/818/1/19 ◽

2016 ◽

Vol 818 (1) ◽

pp. 19 ◽

Cited By ~ 53

Author(s):

J. I. Katz

Keyword(s):

Radio Burst ◽

Burst Pulse ◽

Dispersion Measures ◽

Fast Radio Burst

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Joint inference on the redshift distribution of fast radio burst and on the intergalactic baryon content

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3963 ◽

2020 ◽

Author(s):

S Hackstein ◽

M Brüggen ◽

F Vazza

Keyword(s):

Radio Burst ◽

Intergalactic Medium ◽

Local Environment ◽

Dispersion Measure ◽

Selection Effects ◽

Radio Bursts ◽

Host Galaxies ◽

Redshift Distribution ◽

Joint Inference ◽

Fast Radio Burst

Abstract Context: Fast radio bursts are transient radio pulses of extragalactic origin. Their dispersion measure is indicative of the baryon content in the ionized intergalactic medium between the source and the observer. However, inference using unlocalized fast radio bursts is degenerate to the distribution of redshifts of host galaxies. Method: We perform a joint inference of the intergalactic baryon content and the fast radio burst redshift distribution with the use of Bayesian statistics by comparing the likelihood of different models to reproduce the observed statistics in order to infer the most likely models. In addition to two models of the intergalactic medium, we consider contributions from the local environment of the source, assumed to be a magnetar, as well as a representative ensemble of host and intervening galaxies. Results: Assuming that the missing baryons reside in the ionized intergalactic medium, our results suggest that the redshift distribution of observed fast radio bursts peaks at z ≲ 0.6. However, conclusions from different instruments regarding the intergalactic baryon content diverge and thus require additional changes to the observed distribution of host redshifts, beyond those caused by telescope selection effects.

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Sub-second periodicity in a fast radio burst

10.21203/rs.3.rs-726646/v1 ◽

2021 ◽

Author(s):

Bridget C. Andersen ◽

Kevin Bandura ◽

Mohit Bhardwaj ◽

P. J. Boyle ◽

Charanjot Brar ◽

...

Keyword(s):

Neutron Star ◽

Binary System ◽

Radio Burst ◽

Radio Bursts ◽

Radio Waves ◽

Pulse Profile ◽

Intensity Mapping ◽

Giant Pulses ◽

Component Pulse ◽

Fast Radio Burst

Abstract The origin of fast radio bursts (FRBs), millisecond-duration flashes of radio waves that are visible at distances of billions of light-years, remains an open astrophysical question. Here we report the detection of the multi-component FRB 20191221A with the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB), and the identification of a periodic separation of 216.8(1) ms between its components with a significance of 6.5 sigmas. The long (~ 3 s) duration and nine or more components forming the pulse profile make this source an outlier in the FRB population. We also report two additional FRBs, 20210206A and 20210213A, whose multi-component pulse profiles show some indication of periodic separations of 2.8(1) and 10.7(1) ms, respectively, suggesting the possible existence of a group of FRBs with complex and periodic pulse profiles. Such short periodicities provide strong evidence for a neutron-star origin of these events. Moreover, our detections favour emission arising from the neutron-star magnetosphere, as opposed to emission regions located further away from the star, as predicted by some models. Possible explanations for the observed periodicity include super-giant pulses from a neutron star that are possibly related to a magnetar outburst and interacting neutron stars in a binary system.

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Fast radio burst dispersion measures and rotation measures and the origin of intergalactic magnetic fields

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2033 ◽

2019 ◽

Vol 488 (3) ◽

pp. 4220-4238 ◽

Cited By ~ 7

Author(s):

S Hackstein ◽

M Brüggen ◽

F Vazza ◽

B M Gaensler ◽

V Heesen

Keyword(s):

Magnetic Fields ◽

Radio Burst ◽

Milky Way ◽

Intergalactic Medium ◽

Local Environment ◽

Distribution Functions ◽

Host Galaxy ◽

Radio Bursts ◽

Dispersion Measures ◽

Fast Radio Burst

ABSTRACT We investigate the possibility of measuring intergalactic magnetic fields using the dispersion measures and rotation measures of fast radio bursts. With Bayesian methods, we produce probability density functions for values of these measures. We distinguish between contributions from the intergalactic medium, the host galaxy, and the local environment of the progenitor. To this end, we use constrained, magnetohydrodynamic simulations of the local Universe to compute lines-of-sight integrals from the position of the Milky Way. In particular, we differentiate between predominantly astrophysical and primordial origins of magnetic fields in the intergalactic medium. We test different possible types of host galaxies and probe different distribution functions of fast radio burst progenitor locations inside the host galaxy. Under the assumption that fast radio bursts are produced by magnetars, we use analytic predictions to account for the contribution of the local environment. We find that less than 100 fast radio bursts from magnetars in stellar-wind environments hosted by starburst dwarf galaxies at redshift z ≳ 0.5 suffice to discriminate between predominantly primordial and astrophysical origins of intergalactic magnetic fields. However, this requires the contribution of the Milky Way to be removed with a precision of ≈1 rad m−2. We show the potential existence of a subset of fast radio bursts whose rotation measures carry information on the strength of the intergalactic magnetic field and its origins.

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