Periodicities observed in two Fast Radio Burst (FRB) sources (16 days in FRB 180916.J0158+65 and 160 days in FRB 121102) are consistent with that of tight, stellar mass binary systems. In the case of FRB 180916.J0158+65 the primary is an early OB-type star with mass loss rate $\dot{M} \sim 10^{-8}- 10^{-7} M_\odot$ yr$^{-1}$, and the secondary a neutron star. The observed periodicity is not intrinsic to the FRB's source, but is due to the orbital phase-dependent modulation of the absorption conditions in the massive star's wind. The observed relatively narrow FRB activity window implies that the primary's wind dynamically dominates that of the pulsar, $η= L_{sd}/(\dot{M} v_w c) \leq 1$, where $L_{sd} $ is pulsar spin-down, $\dot{M}$ is the primary's wind mass loss rate and $v_w$ is its velocity. The condition $η\leq 1$ requires mildly powerful pulsar with $L_{sd} \lesssim 10^{37}$ erg $s^{-1}$. The observations are consistent with magnetically-powered radio emission originating in the magnetospheres of strongly magnetized neutron stars, the classical magnetars.
Popular Fast Radio Burst models involve rotating magnetized neutron stars, yet no rotational periodicities have been found. Small datasets exclude exact periodicity in FRB 121102. Recent observations of over 1500 bursts from each of FRB 121102 and FRB 20201124A also have not found periodicity. Periodograms of events with cosine-distributed random offsets as large as $\pm 0.6 P$ from a strict period $P$ would still reveal the underlying periodicity. The sensitivity of periodograms of long data series, such as bursts observed on multiple days, to slow frequency drifts is mitigated by considering…
Recent observations of the periodic Fast Radio Burst source 180916.J0158+65 (FRB 180916) find small linear polarization position angle swings during and between bursts, with a burst activity window that becomes both narrower and earlier at higher frequencies. Although the observed chromatic activity window disfavors models of periodicity in FRB 180916 driven by the occultation of a neutron star by the optically-thick wind from a stellar companion, the connection to theories where periodicity arises from the motion of a bursting magnetar remains unclear. In this paper, we show how altitude-depe…
We show that the 216.8$\pm$0.1 ms periodicity reported for the fast radio burst (FRB) 20191221A is very constraining for burst models. The high accuracy of burst periodicity (better than one part in 10$^3$), and the 2\% duty cycle (ratio of burst-duration and inter-burst interval), suggest a pulsar-like rotating beam model for the observed activity; the radio waves are produced along open field lines within $\sim 10^7$ cm of the neutron star surface, and the beam periodically sweeps across the observer as the star spins. According to this picture, FRB 20191221A is a factor $\sim 10^{12}$ scale…
We report the findings of a uGMRT observing campaign on FRB 180916.J0158+65, discovered recently to show a 16.35-day periodicity of its active cycle. We observed the source at 550-750 MHz for $\sim 2$ hours each during three successive cycles at the peak of its expected active period. We find 0, 12, and 3 bursts respectively, implying a highly variable bursting rate even within the active phase. We consistently detect faint bursts with spectral energies only an order of magnitude higher than the Galactic burst source SGR~1935+2154. The times of arrival of the detected bursts rule out many poss…
The CHIME/FRB collaboration recently reported the detection of a 16 day periodicity in the arrival times of radio bursts from FRB 180916.J0158+65. We study the possibility that the observed periodicity arises from free precession of a magnetized neutron star, and put constraints on different components of the star's magnetic fields. Using a simple geometric model, where radio bursts are emitted from a rotating neutron star magnetosphere, we show that the emission pattern as a function of time can match that observed from FRB 180916.J0158+65.
The recurrent fast radio burst FRB 180916 was recently shown to exhibit a 16 day period (with possible aliasing) in its bursting activity. Given magnetars as widely considered FRB sources, this period has been attributed to precession of the magnetar spin axis or the orbit of a binary companion. Here, we make the simpler connection to a {\it rotational period}, an idea observationally motivated by the 6.7 hour period of the Galactic magnetar candidate, 1E 161348--5055. We explore three physical mechanisms that could lead to the creation of ultra long period magnetars: (i) enhanced spin-down du…
Detections from the repeating fast radio burst FRB 121102 are clustered in time, noticeable even in the earliest repeat bursts. Recently, it was argued that the source activity is periodic, suggesting that the clustering reflected a not-yet-identified periodicity. We performed an extensive multi-wavelength campaign with the Effelsberg telescope, the Green Bank telescope and the Arecibo Observatory to shadow the Gran Telescope Canaria (optical), NuSTAR (X-ray) and INTEGRAL (gamma-ray). We detected 36 bursts with Effelsberg, one with a pulse width of 39\,ms, the widest burst ever detected from F…
The light curve of the fast radio burst (FRB) 181112 is resolved into four successive pulses, and the time interval ($\sim0.8$ ms) between the first and third pulses coincides with that between the second and fourth pulses, which can be interpreted as a neutron star (NS) spinning at a period of about $0.8$ ms. Although this period is shorter than the most rapidly rotating pulsar currently known ($1.4$ ms), it is typical for a simulated massive NS formed immediately after the coalescence of binary neutron stars (BNS). Therefore, a BNS merger is a good candidate for the origin of this FRB if the…
Searching for links between energetic millisecond pulsars and repeating fast radio bursts
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）；Department of Physics, McGill University（麦吉尔大学物理系）；Trottier Space Institute, McGill University（麦吉尔大学特罗蒂尔太空研究所）；Joint institute for VLBI ERIC（甚长基线干涉测量联合研究所 ERIC）；CSIRO Space and Astronomy, Australia Telescope National Facility（澳大利亚联邦科学与工业研究组织空间与天文部，澳大利亚望远镜国家设施）
We report the properties of more than 800 bursts detected from the repeating fast radio burst (FRB) source FRB 20201124A with the Five-hundred-meter Aperture Spherical radio telescope (FAST) during an extremely active episode on UTC September 25th-28th, 2021 in a series of four papers. In this fourth paper of the series, we present a systematic search of the spin period and linear acceleration of the source object from both 996 individual pulse peaks and the dedispersed time series. No credible spin period was found from this data set. We rule out the presence of significant periodicity in the…
Fast radio bursts (FRBs) are millisecond-duration flashes of radio waves that are visible at distances of billions of light-years. The nature of their progenitors and their emission mechanism remain open astrophysical questions. Here we report the detection of the multi-component FRB 20191221A 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. Such short periodicity provides strong evidence for a …
Recently, repeating fast radio bursts (FRBs) with a period of $P_{\rm FRB}=16.35\pm0.18$ days from FRB 180916.J0158+65 had been reported. It still remains controversial how to give rise to such a periodicity of this FRB. In this Letter, based on an assumption of a young pulsar surrounding by a debris disk, we attempt to diagnose whether the Lense-Thirring precession of the disk on the emitter can produce the observed periodicity. Our calculations indicate that the Lense-Thirring effect of a tilted disk can result in a precession period of 16 days for a mass inflow rate of $0.5-1.5\times10^{18}…
We analyze the slow periodicities identified in burst sequences from FRB 121102 and FRB 180916 with periods of about 16 and 160 d, respectively, while also addressing the absence of any fast periodicity that might be associated with the spin of an underlying compact object. Both phenomena can be accounted for by a young, highly magnetized, precessing neutron star that emits beamed radiation with significant imposed phase jitter. Sporadic narrow-beam emission into an overall wide solid angle can account for the necessary phase jitter, but the slow periodicities with 25 to 55 % duty cycles const…
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 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 pulsar…
Fast radio bursts (FRBs) are bright, millisecond-duration radio transients originating from extragalactic distances. Their origin is unknown. Some FRB sources emit repeat bursts, ruling out cataclysmic origins for those events. Despite searches for periodicity in repeat burst arrival times on time scales from milliseconds to many days, these bursts have hitherto been observed to appear sporadically, and though clustered, without a regular pattern. Here we report the detection of a $16.35\pm0.15$ day periodicity (or possibly a higher-frequency alias of that periodicity) from a repeating FRB 180…
Observation of fast radio bursts (FRBs) are rising very quickly with the advent of specialised instruments and surveys, and it has recently been shown that some of them repeat quasi-periodically. In particular, evidence of a $P=16.35$ day period has been reported for FRB 180916.J0158+65. We seek an explanation within the frame of our orbiting asteroid model, whereby FRBs are produced in the plasma wake of asteroids immersed in the wind of a pulsar or a magnetar. We used the data reported by the CHIME/FRB collaboration in order to infer the orbital characteristics of asteroid swarms, and perfor…
Recently, the discovery of Galactic FRB 200428 associated with a X-ray burst (XRB) of SGR 1935+2154 has built a bridge between FRBs and magnetar activities. In this paper, we assume that the XRB occurs in the magnetar magnetosphere. We show that the observational properties of FRB 200428 and the associated XRB are consistent with the predictions of synchrotron maser emission at ultrarelativistic magnetized shocks, including radiation efficiency, similar energy occurrence frequency distributions, and simultaneous arrive times. It requires that the upstream medium is a mildly relativistic baryon…
The discovery of periodicity in the arrival times of the fast radio bursts (FRBs) poses a challenge to the oft-studied magnetar scenarios. However, models that postulate that FRBs result from magnetized shocks or magnetic reconnection in a relativistic outflow are not specific to magnetar engines; instead, they require only the impulsive injection of relativistic energy into a dense magnetized medium. Motivated thus, we outline a new scenario in which FRBs are powered by short-lived relativistic outflows (``flares'') from accreting black holes or neutron stars, which propagate into the cavity …
Popular models of repeating Fast Radio Bursts (and perhaps of all Fast Radio Bursts) involve neutron stars because of their high rotational or magnetostatic energy densities. These models take one of two forms: giant but rare pulsar-like pulses like those of Rotating RAdio Transients and outbursts like those of Soft Gamma Repeaters. Here I collate the evidence, recently strengthened, against these models, including the absence of Galactic micro-FRB, and attribute the 16 day periodicity of FRB 180916.J0158+65 to the precession of a jet produced by a massive black hole's accretion disc.
We report the detection of 72 new pulses from the repeating fast radio burst FRB 121102 in Breakthrough Listen C-band (4-8 GHz) observations at the Green Bank Telescope. The new pulses were found with a convolutional neural network in data taken on August 26, 2017, where 21 bursts have been previously detected. Our technique combines neural network detection with dedispersion verification. For the current application we demonstrate its advantage over a traditional brute-force dedis- persion algorithm in terms of higher sensitivity, lower false positive rates, and faster computational speed. To…
Long-term periodicity in the rate of flares is observed for two repeating sources of fast radio bursts (FRBs). In this paper We present a hydrodynamical modeling of a massive binary consisting of a magnetar and an early-type star. We model the interaction of the pulsar wind from the magnetar with an intense stellar wind. It is shown that only during a fraction of the orbital period radio emission can escape the system. This explains the duty cycle of the two repeating FRB sources with periodic activity. The width of the transparency window depends on the eccentricity, stellar wind properties, …
FRB 180916.J0158+65 has been found to repeatedly emit fast radio bursts with the period in roughly 16 days. We propose that such periodicity comes from orbit-induced, spin precession of the emitter, which is possibly a neutron star. Depending on the mass of the companion, the binary period ranges from several hundred to thousands of seconds. Such tight binaries have a relatively short lifetime, which does not likely come from the gravitational decay of a wide binary. We comment on the relation to GW190425 and the possibility in LISA and LIGO detections.
Fast radio bursts (FRBs) are mysterious radio transients with millisecond durations. Recently, a periodic activity of $\sim$16 day and a possible periodicity of $\sim$159 day were detected to arise from FRB 180916.J0158+65 and FRB 121102, respectively, and the spin period of a slow-rotation magnetar was further considered to be one of possibilities to explain the periodic activities of repeating FRBs. For isolated neutron stars, the spin evolution suggests that it's difficult to reach several hours. In this work, we mainly focus on the possible maximum spin period of isolated NSs / magnetars d…
Fast radio bursts (FRBs) are highly energetic radio pulses from cosmological origins. Despite an abundance of detections, their nature remains elusive. At least a subset of FRBs is expected to repeat, as the daily FRB rate surpasses that of any known cataclysmic event, which has been confirmed by observations. One of the proposed mechanisms to generate repeating FRBs is supergiant pulses from young and highly spinning NSs, in which case FRBs could inherit the periodicity of their parent NS. Here we examine the consequences of such a population of periodic fast radio bursts (PFRBs). We calculat…
We present 849 new bursts from FRB 20121102A detected with the 305-m Arecibo Telescope. Observations were conducted as part of our regular campaign to monitor activity and evolution of burst properties. The 10 reported observations were carried out between 1150 and 1730 MHz and fall in the active period around November 2018. All bursts were dedispersed at the same dispersion measure and are consistent with a single value of 562.4(1) pc/cm$^3$. The rate varies between 0 bursts and 218(16) bursts per hour, the highest rate observed to date. The times between consecutive bursts show a bimodal dis…
We derive stringent constraints on the persistent source associated with FRB 121102: Size $10^{17}$ cm $<R<10^{18}$ cm, age $<300$ yr, characteristic electron energy $\varepsilon_e\sim0.3$ GeV, total energy $\sim10^{49}$ erg. The hot radiating plasma is confined by a cold plasma of mass $M_c<0.03 (R/10^{17.5}{\rm cm})^4 M_\odot$. The source is nearly resolved, and may be resolved by 10 GHz observations. The fact that $\varepsilon_e\sim m_p c^2$ suggests that the hot plasma was created by the ejection of a mildly relativistic, $M\sim10^{-5} M_\odot$ shell, which propagated into an extended ambi…
We propose a compact binary model with an eccentric orbit to explain periodically active fast radio burst (FRB) sources, where the system consists of a neutron star (NS) with strong dipolar magnetic fields and a magnetic white dwarf (WD). In our model, the WD fills its Roche lobe at periastron, and mass transfer occurs from the WD to the NS around this point. The accreted material may be fragmented into a number of parts, which arrive at the NS at different times. The fragmented magnetized material may trigger magnetic reconnection near the NS surface. The electrons can be accelerated to an ul…
Exploring the optical properties of redback pulsars: The case of J1717+4308A in the globular cluster M92
Beijing Normal University（北京师范大学）；Alma Mater Studiorum Università di Bologna（博洛尼亚大学）；INAF-Osservatorio di Astrofisica e Scienze dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天文与空间科学观测站）；Norwegian University of Science and Technology（挪威科技大学）
