First discovery of new pulsars and RRATs with CHIME/FRB
D. C. Good, B. C. Andersen, P. Chawla, K. Crowter, F. Q. Dong, E. Fonseca, B. W. Meyers, C. Ng, Z. Pleunis, S. M. Ransom, I. H. Stairs, C. M. Tan, M. Bhardwaj, … 展开作者
D. C. Good, B. C. Andersen, P. Chawla, K. Crowter, F. Q. Dong, E. Fonseca, B. W. Meyers, C. Ng, Z. Pleunis, S. M. Ransom, I. H. Stairs, C. M. Tan, M. Bhardwaj, P. J. Boyle, M. Dobbs, B. M. Gaensler, V. M. Kaspi, K. W. Masui, A. Naidu, M. Rafiei-Ravandi, P. Scholz, K. M. Smith, S. P. Tendulkar
We report the discovery of seven new Galactic pulsars with the Canadian Hydrogen Intensity Mapping Experiment's Fast Radio Burst backend (CHIME/FRB). 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 (RRATs), 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 three. 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.
We report on a search for host galaxies of a subset of Rotating Radio Transients (RRATs) that possess a dispersion measure (DM) near or above the maximum Galactic value in their direction. These RRATs could have an extragalactic origin and therefore be Fast Radio Bursts (FRBs). The sizes of related galaxies on the sky at such short distances are comparable to the beam size of a single-dish telescope (for example, the $7.0'$ radius of the Parkes beam). Hence the association, if found, could be more definitive as compared to finding host galaxies for more distant FRBs. We did not find any host g…
In this paper we consider the fact that the simple criterion used to label fast radio transient events as either fast radio bursts (FRBs, thought to be extragalactic with as yet unknown progenitors) or rotating radio transients (RRATs, thought to be Galactic neutron stars) is uncertain. We identify single pulse events reported in the literature which have never been seen to repeat, and which have been labelled as RRATs, but are potentially mis-labelled FRBs. We examine the probability that such `grey area' events are within the Milky Way. The uncertainty in the RRAT/FRB labelling criterion, as…
In this work, we present follow-up observations of two known repeating fast radio bursts (FRBs) and seven non-repeating FRBs with complex morphology discovered with CHIME/FRB. These observations were conducted with the Arecibo Observatory 327 MHz receiver. We detected no additional bursts from these sources, nor did CHIME/FRB detect any additional bursts from these sources during our follow-up program. Based on these non-detections, we provide constraints on the repetition rate, for all nine sources. We calculate repetition rates above 1 Jy using both a Poisson distribution of repetition and t…
We study the statistical property of fast radio bursts (FRBs) based on a selected sample of 190 one-off FRBs in the first CHIME/FRB catalog. Three power law models are used in the analysis, and we find the cumulative distribution functions of energy can be well fitted by bent power law and thresholded power law models. And the distribution functions of fluctuations of energy well follow the Tsallis $q$-Gaussian distribution. The $q$ values in the Tsallis $q$-Gaussian distribution are constant with small fluctuations for different temporal scale intervals, indicating a scale-invariant structure…
A series of unfortunate events: CHIME/FRB misclassification of a Galactic pulsar as a periodic fast radio burst
McGill University（麦吉尔大学）；Trottier Space Institute, McGill University（麦克唐纳空间研究所，麦吉尔大学）；University of California, Santa Cruz（加州大学圣克鲁兹分校）；Indian Institute of Technology Kanpur（坎普尔印度理工学院）；Universidad de Chile（智利大学）；Cornell Center for Astrophysics and Planetary Science, Cornell University（康奈尔大学天体物理学与行星科学中心，康奈尔大学）；University of British Columbia（不列颠哥伦比亚大学）；West Virginia University（西弗吉尼亚大学）；Center for Gravitational Waves and Cosmology, West Virginia University（引力波与宇宙学中心，西弗吉尼亚大学）
We report on the discovery and analysis of bursts from nine new repeating fast radio burst (FRB) sources found using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These sources span a dispersion measure (DM) range of 195 to 1380 pc cm$^{-3}$. We detect two bursts from three of the new sources, three bursts from four of the new sources, four bursts from one new source, and five bursts from one new source. We determine sky coordinates of all sources with uncertainties of $\sim$10$^\prime$. We detect Faraday rotation measures for two sources, with values $-20(1)$ and $-499…
Advanced LIGO and Virgo have reported 90 confident gravitational-wave (GW) observations from compact-binary coalescences from their three observation runs. In addition, numerous subthreshold gravitational-wave candidates have been identified. Binary neutron star (BNS) mergers can produce gravitational waves and short-gamma ray bursts, as confirmed by GW170817/GRB 170817A. There may be electromagnetic counterparts recorded in archival observations associated with subthreshold gravitational-wave candidates. The CHIME/FRB Collaboration has reported the first large sample of fast radio bursts (FRB…
We present a synthesis of fast radio burst (FRB) morphology (the change in flux as a function of time and frequency) as detected in the 400-800 MHz octave by the FRB project on the Canadian Hydrogen Intensity Mapping Experiment (CHIME/FRB), using events from the first CHIME/FRB catalog. The catalog consists of 61 bursts from 18 repeating sources, plus 474 one-off FRBs, detected between 2018 July 25 and 2019 July 2. We identify four observed archetypes of burst morphology ("simple broadband," "simple narrowband," "temporally complex" and "downward drifting") and describe relevant instrumental b…
Radio Monitoring Campaign of Active Repeater FRB 20220912A with CHIME
McGill University（麦吉尔大学）；MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理与空间研究所）；Massachusetts Institute of Technology（麻省理工学院）；Tel Aviv University（特拉维夫大学）；National Research Council of Canada, Herzberg Astronomy and Astrophysics（加拿大国家研究委员会赫茨伯格天文学与天体物理学研究所）；University of British Columbia（不列颠哥伦比亚大学）
Extreme-Value Distribution Analysis of the Second CHIME/FRB Catalog: Assessing the Rarity of the One-off FRB 20250316A
Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；School of Astronomy and Space Sciences, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）
The redshift distribution of fast radio bursts (FRBs) is not well constrained. The association of the Galactic FRB 200428 with the young magnetar SGR 1935+2154 raises the working hypothesis that FRB sources track the star formation history of the universe. The discovery of FRB 20200120E in association with a globular cluster in the nearby galaxy M81, however, casts doubts on such an assumption. We apply the Monte Carlo method developed in a previous work to test different FRB redshift distribution models against the recently released first CHIME FRB catalog in terms of their distributions in s…
Observationally, the mysterious fast radio bursts (FRBs) are classified as repeating ones and apparently non-repeating ones. While repeating FRBs cannot be classified into the non-repeating group, it is unknown whether the apparently non-repeating FRBs are actually repeating FRBs whose repetitions are yet to be discovered, or whether they belong to another physically distinct type from the repeating ones. In a series of two papers, we attempt to disentangle this mystery with machine learning methods. In this first paper, we focus on an array of supervised machine learning methods. We train the…
Fast radio bursts (FRBs) are extremely strong radio flares lasting several micro- to milliseconds and come from unidentified objects at cosmological distances, most of which are only seen once. Based on recently published data in the CHIME/FRB Catalog 1 in the frequency bands 400-800 MHz, we analyze 125 apparently singular FRBs with low dispersion measure (DM) and find that the distribution of their luminosity follows a lognormal form according to statistical tests. In our luminosity measurement, the FRB distance is estimated by using the Macquart relation which was obtained for 8 localized FR…
We describe a pipeline to measure scintillation in fast radio bursts (FRBs) detected by CHIME/FRB in the 400-800 MHz band by analyzing the frequency structure of the FRB's spectrum. We use the pipeline to measure the characteristic frequency bandwidths of scintillation between $4-100$ kHz in 12 FRBs corresponding to timescales of $\sim$2-40 $μ$s for 10 FRBs detected by CHIME/FRB. For the other two FRBs, we did not detect scintillation in the region our analysis is sensitive. We compared the measured scintillation timescales to the NE2001 predictions for the scintillation timescales from the Mi…
Constraints on the Physical Association between ICECAT1 Neutrinos and Fast Radio Bursts Using the Second CHIME/FRB Catalogue
The University of Tokyo（东京大学）；National Astronomical Observatory of Japan（日本国立天文台）；Mizusawa VLBI Observatory, National Astronomical Observatory of Japan（水泽甚长基线干涉测量观测站，日本国立天文台）；Department of Physics, National Chung Hsing University（国立中兴大学物理学系）；SOKENDAI（综合研究大学院大学）；Tohoku University（东北大学）；Frontier Research Institute for Interdisciplinary Sciences, Tohoku University（东北大学跨学科前沿研究院）；Astronomical Institute, Graduate School of Science, Tohoku University（东北大学理学研究科天文学研究所）
As the Canadian Hydrogen Intensity Mapping Experiment (CHIME) has become the leading instrument for detecting Fast Radio Bursts (FRBs), CHIME/FRB Outriggers will use very-long-baseline interferometry (VLBI) to localize FRBs with milliarcsecond precision. The CHIME site uses a passive hydrogen maser frequency standard in order to minimize localization errors due to clock delay. However, not all outrigger stations will have access to a maser. This report presents techniques used to evaluate clocks for use at outrigger sites without a maser. More importantly, the resulting algorithm provides cali…
Searching for Gamma Ray Bursts associated with CHIME Fast Radio bursts
Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）；School of Astronomy and Space Sciences, University of Science and Technology of China（中国科学技术大学天文与空间科学学院）；State Key Laboratory of Radio Astronomy and Technology, Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台射电天文与技术国家重点实验室）；South-Western Institute for Astronomy Research, Yunnan University（云南大学西南天文研究所）
The identification and localization of Fast Radio Bursts to their host galaxies has revealed important details about the progenitors of these mysterious, millisecond-long bursts of coherent radio emission. In this work we study the most probable host galaxy of the apparently non-repeating CHIME/FRB event FRB 20190425A -- a particularly high luminosity, low dispersion measure event that was demonstrated by Moroianu et al. 2022 to be temporally and spatially coincident with the LIGO-Virgo-KAGRA binary neutron star merger GW190425, suggesting an astrophysical association (p-value 0.0052). In this…
Discovery of 30 Repeating Fast Radio Burst Sources and Uniform Population Statistics of 80 Repeating Sources from CHIME/FRB
McGill University（麦吉尔大学）；University of Amsterdam（阿姆斯特丹大学）；California Institute of Technology（加州理工学院）；Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）
We search for a spatial association between the CHIME FRBs and IceCube neutrinos detected in the TeV energy range, by counting the total number of neutrino-FRB pairs with angular separations of $< 3 $ degrees, as well as within the observed neutrino error circle. This number constitutes the total signal events, which is then compared to the total background, corresponding to the null hypothesis of no spatial association. The background was obtained from the total neutrino-FRB matches in off-source angular windows with the same solid angle as the signal window. We do not find any statistically …
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) has become a leading facility for detecting fast radio bursts (FRBs) through the CHIME/FRB backend. CHIME/FRB searches for fast transients in polarization-summed intensity data streams that have 24-kHz spectral and 1-ms temporal resolution. The intensity beams are pointed to pre-determined locations in the sky. A triggered baseband system records the coherent electric field measured by each antenna in the CHIME array at the time of FRB detections. Here we describe the analysis techniques and automated pipeline developed to process thes…
Fast radio bursts (FRBs) are one of the most mysterious astronomical transients. Observationally, they can be classified into repeaters and apparently non-repeaters. However, due to the lack of continuous observations, some apparently repeaters may have been incorrectly recognized as non-repeaters. In a series of two papers, we intend to solve such problem with machine learning. In this second paper of the series, we focus on an array of unsupervised machine learning methods. We apply multiple unsupervised machine learning algorithms to the first CHIME/FRB catalog to learn their features and c…
The CHIME/FRB Project has recently released its first catalog of fast radio bursts (FRBs), containing 492 unique sources. We present results from angular cross-correlations of CHIME/FRB sources with galaxy catalogs. We find a statistically significant ($p$-value $\sim 10^{-4}$, accounting for look-elsewhere factors) cross-correlation between CHIME FRBs and galaxies in the redshift range $0.3 \lesssim z \lesssim 0.5$, in three photometric galaxy surveys: WISE$\times$SCOS, DESI-BGS, and DESI-LRG. The level of cross-correlation is consistent with an order-one fraction of the CHIME FRBs being in t…
We report on the discovery of eight repeating fast radio burst (FRB) sources found using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These sources span a dispersion measure (DM) range of 103.5 to 1281 pc cm$^{-3}$. They display varying degrees of activity: six sources were detected twice, another three times, and one ten times. These eight repeating FRBs likely represent the bright and/or high-rate end of a distribution of infrequently repeating sources. For all sources, we determine sky coordinates with uncertainties of $\sim$10$^\prime$. FRB 180916.J0158+65 has a bu…
Probing the maximum energy of fast radio bursts using thousands of sources from the Second CHIME/FRB Catalog
McGill University（麦吉尔大学）；Trottier Space Institute, McGill University（特罗蒂尔空间研究所，麦吉尔大学）；Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安东·潘内科克天文学研究所）；ASTRON, Netherlands Institute for Radio Astronomy（荷兰射电天文研究所 ASTRON）；School of Physics and Astronomy, Tel Aviv University（特拉维夫大学物理与天文学学院）；MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理学与空间研究研究所）；Department of Physics, Massachusetts Institute of Technology（麻省理工学院物理系）
We present a newly implemented single-pulse pipeline for the PALFA survey to efficiently identify single radio pulses from pulsars, Rotating Radio Transients (RRATs) and Fast Radio Bursts (FRBs). We have conducted a sensitivity analysis of this new pipeline in which multiple single pulses with a wide range of parameters were injected into PALFA data sets and run through the pipeline. Based on the recovered pulses, we find that for pulse widths $\rm < 5\ ms$ the sensitivity of the PALFA pipeline is at most a factor of $\rm \sim 2$ less sensitive to single pulses than our theoretical predictions…
The observed Fast Radio Burst (FRB) population can be divided into one-off and repeating FRB sources. Either this division is a true dichotomy of the underlying sources, or selection effects and low activity prohibit us from observing repeat pulses from all constituents making up the FRB source population. We attempt to break this degeneracy through FRB population synthesis. With that aim we extend frbpoppy, which earlier only handled one-off FRBs, to also simulate repeaters. We next model the Canadian Hydrogen Intensity Mapping Experiment FRB survey (CHIME/FRB). Using this implementation, we …
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a novel transit radio telescope operating across the 400-800-MHz band. CHIME is comprised of four 20-m x 100-m semi-cylindrical paraboloid reflectors, each of which has 256 dual-polarization feeds suspended along its axis, giving it a >200 square degree field-of-view. This, combined with wide bandwidth, high sensitivity, and a powerful correlator makes CHIME an excellent instrument for the detection of Fast Radio Bursts (FRBs). The CHIME Fast Radio Burst Project (CHIME/FRB) will search beam-formed, high time-and frequency-resolution…
The Parkes, ASKAP, CHIME and UTMOST telescopes, which have all detected FRBs, each works at a different frequency and has a different detection criteria. Using simulations, we have combined the constraints from all four telescopes to identify an allowed range of model parameters $(α, \E33)$ for the FRB source population. Here $α$ is the spectral index and $\E33$ is the mean FRB energy in units of $10^{33} \, {\rm J}$ across a $2128 - 2848\; {\rm MHz}$ band in the FRB rest frame. We have considered several different FRB energy distributions, and also different scenarios for the scattering pulse…
We demonstrate the blind interferometric detection and localization of two fast radio bursts (FRBs) with 2- and 25-arcsecond precision on the 400-m baseline between the Canadian Hydrogen Intensity Mapping Experiment (CHIME) and the CHIME Pathfinder. In the same spirit as very long baseline interferometry (VLBI), the telescopes were synchronized to separate clocks, and the channelized voltage (herein referred to as "baseband") data were saved to disk with correlation performed offline. The simultaneous wide field of view and high sensitivity required for blind FRB searches implies a high data r…
