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

2020 ◽  
Vol 494 (1) ◽  
pp. 1229-1236 ◽  
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.

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

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.

scholarly journals A search for fast-radio-burst-like emission from Fermi gamma-ray bursts

2020 ◽  
Vol 497 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Mieke Bouwhuis ◽  
Keith W Bannister ◽  
Jean-Pierre Macquart ◽  
R M Shannon ◽  
David L Kaplan ◽  
...  
Keyword(s):  
Radio Emission ◽  
Radio Burst ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Dispersion Measure ◽  
Radio Bursts ◽  
Square Kilometre Array ◽  
Fast Radio Burst ◽  
Short Grbs

ABSTRACT We report the results of the rapid follow-up observations of gamma-ray bursts (GRBs) detected by the Fermi satellite to search for associated fast radio bursts. The observations were conducted with the Australian Square Kilometre Array Pathfinder at frequencies from 1.2 to 1.4 GHz. A set of 20 bursts, of which four were short GRBs, were followed up with a typical latency of about 1 min, for a duration of up to 11 h after the burst. The data were searched using 4096 dispersion measure trials up to a maximum dispersion measure of 3763 pc cm−3, and for pulse widths w over a range of duration from 1.256 to 40.48 ms. No associated pulsed radio emission was observed above $26 \, {\rm Jy\, ms}\, (w/1\, {\rm ms})^{-1/2}$ for any of the 20 GRBs.

scholarly journals Multiwavelength Observations of Fast Radio Bursts

Universe ◽  
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.

scholarly journals Fast radio burst dispersion measure distribution as a probe of helium reionization

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
Mukul Bhattacharya ◽  
Pawan Kumar ◽  
Eric V. Linder
Keyword(s):  
Radio Burst ◽  
Dispersion Measure ◽  
Fast Radio Burst ◽  
Measure Distribution

scholarly journals A fast radio burst with a low dispersion measure

2018 ◽  
Author(s):  
E Petroff ◽  
L C Oostrum ◽  
B W Stappers ◽  
M Bailes ◽  
E D Barr ◽  
...  
Keyword(s):  
Radio Burst ◽  
Dispersion Measure ◽  
Fast Radio Burst ◽  
Low Dispersion

scholarly journals Pulsar science with the CHIME telescope

2017 ◽  
Vol 13 (S337) ◽  
pp. 179-182 ◽  
Author(s):  
Cherry Ng
Keyword(s):  
Northern Hemisphere ◽  
Radio Telescope ◽  
Field Of View ◽  
Radio Bursts ◽  
Radio Telescopes ◽  
Acoustic Oscillations ◽  
Daily Monitoring ◽  
Intensity Mapping ◽  
Pulsar Timing ◽  
Pulsar Timing Array

AbstractThe CHIME telescope (the Canadian Hydrogen Intensity Mapping Experiment) recently built in Penticton, Canada, is currently being commissioned. Originally designed as a cosmology experiment, it was soon recognized that CHIME has the potential to simultaneously serve as an incredibly useful radio telescope for pulsar science. CHIME operates across a wide bandwidth of 400–800 MHz and will have a collecting area and sensitivity comparable to that of the 100-m class radio telescopes. CHIME has a huge field of view of ~250 square degrees. It will be capable of observing 10 pulsars simultaneously, 24-hours per day, every day, while still accomplishing its missions to study Baryon Acoustic Oscillations and Fast Radio Bursts. It will carry out daily monitoring of roughly half of all pulsars in the northern hemisphere, including all NANOGrav pulsars employed in the Pulsar Timing Array project. It will cycle through all pulsars in the northern hemisphere with a range of cadence of no more than 10 days.

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

2021 ◽  
Vol 923 (1) ◽  
pp. 2 ◽  
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.

scholarly journals A Decade and a Half of Fast Radio Burst Observations

Universe ◽  
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.

scholarly journals Young magnetars with fracturing crusts as fast radio burst repeaters

2019 ◽  
Vol 488 (4) ◽  
pp. 5887-5897 ◽  
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.

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

2019 ◽  
Vol 36 ◽  
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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