scholarly journals First Discovery of New Pulsars and RRATs with CHIME/FRB

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.

scholarly journals PALFA Single-pulse Pipeline: New Pulsars, Rotating Radio Transients, and a Candidate Fast Radio Burst

2018 ◽  
Vol 869 (2) ◽  
pp. 181 ◽  
Author(s):  
C. Patel ◽  
D. Agarwal ◽  
M. Bhardwaj ◽  
M. M. Boyce ◽  
A. Brazier ◽  
...  
Keyword(s):  
Radio Burst ◽  
Single Pulse ◽  
Fast Radio Burst ◽  
Radio Transients ◽  
Rotating Radio Transients

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

2019 ◽  
Vol 36 ◽  
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.

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 Radio Properties of Rotating Radio Transients: Single-pulse Spectral and Wait-time Analyses

2018 ◽  
Vol 866 (2) ◽  
pp. 152
Author(s):  
B. J. Shapiro-Albert ◽  
M. A. McLaughlin ◽  
E. F. Keane
Keyword(s):  
Wait Time ◽  
Single Pulse ◽  
Radio Transients ◽  
Rotating Radio Transients

scholarly journals Comprehensive Analysis of a Dense Sample of FRB 121102 Bursts

2021 ◽  
Vol 922 (2) ◽  
pp. 115
Author(s):  
Kshitij Aggarwal ◽  
Devansh Agarwal ◽  
Evan F. Lewis ◽  
Reshma Anna-Thomas ◽  
Jacob Cardinal Tremblay ◽  
...  
Keyword(s):  
Radio Burst ◽  
Single Pulse ◽  
Center Frequency ◽  
Robust Fitting ◽  
Link Type ◽  
Temporal Properties ◽  
Fast Radio Burst ◽  
Log Normal ◽  
Median Width ◽  
Log Normal Distribution

Abstract We present an analysis of a densely repeating sample of bursts from the first repeating fast radio burst, FRB 121102. We reanalyzed the data used by Gourdji et al. and detected 93 additional bursts using our single-pulse search pipeline. In total, we detected 133 bursts in three hours of data at a center frequency of 1.4 GHz using the Arecibo telescope, and develop robust modeling strategies to constrain the spectro-temporal properties of all of the bursts in the sample. Most of the burst profiles show a scattering tail, and burst spectra are well modeled by a Gaussian with a median width of 230 MHz. We find a lack of emission below 1300 MHz, consistent with previous studies of FRB 121102. We also find that the peak of the log-normal distribution of wait times decreases from 207 to 75 s using our larger sample of bursts, as compared to that of Gourdji et al. Our observations do not favor either Poissonian or Weibull distributions for the burst rate distribution. We searched for periodicity in the bursts using multiple techniques, but did not detect any significant period. The cumulative burst energy distribution exhibits a broken power-law shape, with the lower- and higher-energy slopes of −0.4 ± 0.1 and −1.8 ± 0.2, with the break at (2.3 ± 0.2) × 1037 erg. We provide our burst fitting routines as a Python package burstfit 4 4 https://github.com/thepetabyteproject/burstfit that can be used to model the spectrogram of any complex fast radio burst or pulsar pulse using robust fitting techniques. All of the other analysis scripts and results are publicly available. 5 5 https://github.com/thepetabyteproject/FRB121102

Extra-galactic Radio Sources with Extended Structure

1970 ◽  
Vol 1 (7) ◽  
pp. 337-340 ◽  
Author(s):  
R. T. Schilizzi ◽  
W. B. McAdam
Keyword(s):  
Large Fraction ◽  
Small Diameter ◽  
Low Frequency ◽  
Brightness Distribution ◽  
Radio Sources ◽  
Double Structure ◽  
Long Baseline ◽  
Wide Range ◽  
Galactic Sources ◽  
Galactic Radio

Most extra-galactic radio sources show angular structure over a wide range of size. Long-baseline interferometers and scintillation observations have shown that resolved sources extending over 10′ arc can have significant contributions from components <1″ arc. Observations at low frequency with the Molonglo cross telescope show also that a large fraction of the emission can come from halo, bridge or extended regions which may form a diffuse ridge or arc structure extending well beyond the small diameter components. However the majority of sources exhibit a basic double structure, and this has led to the adoption of two extended (Gaussian) components as an initial model for the interpretation of brightness distribution in most papers on the structure of extra-galactic sources. Parameters based on such a model will usually match the observed distribution quite well, but because of confusion, there is a danger in using intensity parameters for a model component to derive the spectral index for part of the source.

Fast Radio Transients: From Pulsars to Fast Radio Bursts

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.

scholarly journals Sub-second periodicity in a fast radio burst

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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