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

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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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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Multiwavelength Observations of Fast Radio Bursts

Universe ◽

10.3390/universe7030076 ◽

2021 ◽

Vol 7 (3) ◽

pp. 76

Author(s):

Luciano Nicastro ◽

Cristiano Guidorzi ◽

Eliana Palazzi ◽

Luca Zampieri ◽

Massimo Turatto ◽

...

Keyword(s):

Radio Burst ◽

High Energy ◽

Medium Size ◽

Radio Bursts ◽

Starting Point ◽

Key Points ◽

Fast Radio Burst ◽

Theoretical Results ◽

Observational Strategy ◽

Shed Light

The origin and phenomenology of the Fast Radio Burst (FRB) remains unknown despite more than a decade of efforts. Though several models have been proposed to explain the observed data, none is able to explain alone the variety of events so far recorded. The leading models consider magnetars as potential FRB sources. The recent detection of FRBs from the galactic magnetar SGR J1935+2154 seems to support them. Still, emission duration and energetic budget challenge all these models. Like for other classes of objects initially detected in a single band, it appeared clear that any solution to the FRB enigma could only come from a coordinated observational and theoretical effort in an as wide as possible energy band. In particular, the detection and localisation of optical/NIR or/and high-energy counterparts seemed an unavoidable starting point that could shed light on the FRB physics. Multiwavelength (MWL) search campaigns were conducted for several FRBs, in particular for repeaters. Here we summarize the observational and theoretical results and the perspectives in view of the several new sources accurately localised that will likely be identified by various radio facilities worldwide. We conclude that more dedicated MWL campaigns sensitive to the millisecond–minute timescale transients are needed to address the various aspects involved in the identification of FRB counterparts. Dedicated instrumentation could be one of the key points in this respect. In the optical/NIR band, fast photometry looks to be the only viable strategy. Additionally, small/medium size radiotelescopes co-pointing higher energies telescopes look a very interesting and cheap complementary observational strategy.

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A Decade and a Half of Fast Radio Burst Observations

Universe ◽

10.3390/universe7110453 ◽

2021 ◽

Vol 7 (11) ◽

pp. 453

Author(s):

Manisha Caleb ◽

Evan Keane

Keyword(s):

Magnetic Field ◽

Radio Burst ◽

Line Of Sight ◽

Radio Bursts ◽

Radio Observations ◽

The Past ◽

Interstellar Media ◽

Propagation Effects ◽

Fast Radio Burst ◽

The Universe

Fast radio bursts (FRBs) have a story which has been told and retold many times over the past few years as they have sparked excitement and controversy since their pioneering discovery in 2007. The FRB class encompasses a number of microsecond- to millisecond-duration pulses occurring at Galactic to cosmological distances with energies spanning about 8 orders of magnitude. While most FRBs have been observed as singular events, a small fraction of them have been observed to repeat over various timescales leading to an apparent dichotomy in the population. ∼50 unique progenitor theories have been proposed, but no consensus has emerged for their origin(s). However, with the discovery of an FRB-like pulse from the Galactic magnetar SGR J1935+2154, magnetar engine models are the current leading theory. Overall, FRB pulses exhibit unique characteristics allowing us to probe line-of-sight magnetic field strengths, inhomogeneities in the intergalactic/interstellar media, and plasma turbulence through an assortment of extragalactic and cosmological propagation effects. Consequently, they are formidable tools to study the Universe. This review follows the progress of the field between 2007 and 2020 and presents the science highlights of the radio observations.

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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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Young magnetars with fracturing crusts as fast radio burst repeaters

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2052 ◽

2019 ◽

Vol 488 (4) ◽

pp. 5887-5897 ◽

Cited By ~ 7

Author(s):

A G Suvorov ◽

K D Kokkotas

Keyword(s):

Statistical Analysis ◽

Power Law ◽

Radio Burst ◽

Rapid Evolution ◽

Compact Objects ◽

Tectonic Activity ◽

Radio Bursts ◽

Crustal Field ◽

Long Time ◽

Fast Radio Burst

Abstract Fast radio bursts are millisecond-duration radio pulses of extragalactic origin. A recent statistical analysis has found that the burst energetics of the repeating source FRB 121102 follow a power law, with an exponent that is curiously consistent with the Gutenberg–Richter law for earthquakes. This hints that repeat bursters may be compact objects undergoing violent tectonic activity. For young magnetars, possessing crustal magnetic fields which are both strong (B ≳ 1015 G) and highly multipolar, Hall drift can instigate significant field rearrangements even on ≲ century long time-scales. This reconfiguration generates zones of magnetic stress throughout the outer layers of the star, potentially strong enough to facilitate frequent crustal failures. In this paper, assuming a quake scenario, we show how the crustal field evolution, which determines the resulting fracture geometries, can be tied to burst properties. Highly anisotropic stresses are generated by the rapid evolution of multipolar fields, implying that small, localized cracks can occur sporadically throughout the crust during the Hall evolution. Each of these shallow fractures may release bursts of energy, consistent in magnitude with those seen in the repeating sources FRB 121102 and FRB 180814.J0422+73.

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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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The Northern Cross fast radio burst project – I. Overview and pilot observations at 408 MHz

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa813 ◽

2020 ◽

Vol 494 (1) ◽

pp. 1229-1236 ◽

Cited By ~ 2

Author(s):

Nicola T Locatelli ◽

Gianni Bernardi ◽

Germano Bianchi ◽

Riccardo Chiello ◽

Alessio Magro ◽

...

Keyword(s):

Radio Burst ◽

System Performance ◽

Field Of View ◽

High Dispersion ◽

Dispersion Measure ◽

Radio Bursts ◽

Radio Telescopes ◽

Present Test ◽

New Radio ◽

Fast Radio Burst

ABSTRACT Fast radio bursts (FRBs) remain one of the most enigmatic astrophysical sources. Observations have significantly progressed over the last few years, due to the capabilities of new radio telescopes and the refurbishment of existing ones. Here, we describe the upgrade of the Northern Cross radio telescope, operating in the 400–416 MHz frequency band, with the ultimate goal of turning the array into a dedicated instrument to survey the sky for FRBs. We present test observations of the pulsar B0329+54 to characterize the system performance and forecast detectability. Observations with the system currently in place are still limited by modest sky coverage (∼9.4 deg2) and biased by smearing of high dispersion measure events within each frequency channels. In its final, upgraded configuration, however, the telescope will be able to carry out unbiased FRB surveys over a ∼350 deg2 instantaneous field of view up to z ∼ 5, with a (nearly constant) $\sim 760 \, (\tau /{\rm ms})^{-0.5}$ mJy rms sensitivity.

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Fast Radio Transients: From Pulsars to Fast Radio Bursts

Proceedings of the International Astronomical Union ◽

10.1017/s1743921318002156 ◽

2017 ◽

Vol 14 (S339) ◽

pp. 27-32

Author(s):

B. W. Stappers ◽

M. Caleb ◽

L. N. Driessen

Keyword(s):

Real Time ◽

Time Scales ◽

Radio Burst ◽

Host Galaxy ◽

Radio Bursts ◽

Recent Developments ◽

New Instrumentation ◽

Fast Radio Burst ◽

Radio Transients ◽

Archived Data

AbstractThe radio sky is full of transients, their time-scales ranging from nanoseconds to decades. Recent developments in technology sensitivity and computing capabilities have opened up the short end of that range, and are revealing a plethora of new phenomenologies. Studies of radio transients were previously restricted to analyses of archived data, but are now including real-time analyses. We focus here on Fast Radio Bursts, discuss and compare the properties of the population, and describe what is to date the only known repeating Fast Radio Burst and its host galaxy. We also review what will be possible with the new instrumentation coming online.

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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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Quark-Novae in the outskirts of galaxies: an explanation of the fast radio burst phenomenon

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3511 ◽

2020 ◽

Vol 500 (4) ◽

pp. 4414-4421

Author(s):

Rachid Ouyed ◽

Denis Leahy ◽

Nico Koning

Keyword(s):

Neutron Stars ◽

Radio Burst ◽

Galactic Halo ◽

Ambient Medium ◽

Collisionless Plasma ◽

Clusters Of Galaxies ◽

Radio Bursts ◽

Quark Star ◽

Coherent Emission ◽

Fast Radio Burst

ABSTRACT We show that old isolated neutron stars in groups and clusters of galaxies experiencing a Quark-Nova phase (QN: an explosive transition to a quark star) may be the source of fast radio bursts (FRBs). Each of the millions of fragments of the ultrarelativistic QN ejecta provides a collisionless plasma for which the ambient medium (galactic/halo, the intragroup/intracluster medium) acts as a relativistic plasma beam. The Buneman and the Weibel instabilities, successively induced by the beam in the fragment, generate particle bunching and observed coherent emission at GHz frequency with a corresponding fluence in the Jy ms range. The duration, frequency drift, and the rate are in agreement with observed properties of FRBs. Repeats (on time-scales of minutes to months) are due to seeing multiple fragments each beaming at a different direction and coming in at different times. Single (non-repeating) FRBs occur when only emission from the primary fragment is within the detector’s sensitivity. Key properties of FRB 121102 (its years of activity) and of FRB 180916.J0158+65 (its ∼16 d period) are recovered. The spatial and temporal coincidence between SGR 1935+2154 and FRB 200428 finds an explanation in our model. We give testable predictions.

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