Multiwavelength Observations of Fast Radio Bursts
TL;DR: In this paper, the authors 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, and 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.
Abstract: 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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TL;DR: In this article, the authors reported on the host association of FRB 20181030A, a repeating fast radio burst (FRB) with a low dispersion measure (DM, 103.5 pc cm$-3}$) discovered by CHIME/FRB Collaboration et al. Using baseband voltage data saved for its repeat bursts, they localize the FRB to a sky area of 5.3 sq. arcmin (90% confidence).
Abstract: We report on the host association of FRB 20181030A, a repeating fast radio burst (FRB) with a low dispersion measure (DM, 103.5 pc cm$^{-3}$) discovered by CHIME/FRB Collaboration et al. (2019a). Using baseband voltage data saved for its repeat bursts, we localize the FRB to a sky area of 5.3 sq. arcmin (90% confidence). Within the FRB localization region, we identify NGC 3252 as the most promising host, with an estimated chance coincidence probability $< 2.5 \times 10^{-3}$. Moreover, we do not find any other galaxy with M$_{r} < -15$ AB mag within the localization region to the maximum estimated FRB redshift of 0.05. This rules out a dwarf host 5 times less luminous than any FRB host discovered to date. NGC 3252 is a star-forming spiral galaxy, and at a distance of $\approx$ 20 Mpc, it is one of the closest FRB hosts discovered thus far. From our archival radio data search, we estimate a 3$\sigma$ upper limit on the luminosity of a persistent compact radio source (source size $<$ 0.3 kpc at 20 Mpc) at 3 GHz to be ${\rm 2 \times 10^{26} erg~s^{-1} Hz^{-1}}$, at least 1500 times smaller than that of the FRB 20121102A persistent radio source. We also argue that a population of young millisecond magnetars alone cannot explain the observed volumetric rate of repeating FRBs. Finally, FRB 20181030A is a promising source for constraining FRB emission models due to its proximity, and we strongly encourage its multi-wavelength follow-up.
26 citations
TL;DR: 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.
Abstract: 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.
15 citations
TL;DR: In this paper, the dispersion measures of fast radio bursts (FRBs) combined with the redshifts of their host galaxies have yielded a direct measurement of the baryon content of the universe, and has the potential to directly constrain the location of the missing baryons.
Abstract: Fast Radio Bursts (FRBs) represent a novel tool for probing the properties of the universe at cosmological distances. The dispersion measures of FRBs, combined with the redshifts of their host galaxies, has very recently yielded a direct measurement of the baryon content of the universe, and has the potential to directly constrain the location of the “missing baryons”. The first results are consistent with the expectations of ΛCDM for the cosmic density of baryons, and have provided the first constraints on the properties of the very diffuse intergalactic medium (IGM) and circumgalactic medium (CGM) around galaxies. FRBs are the only known extragalactic sources that are compact enough to exhibit diffractive scintillation in addition to showing exponential tails which are typical of scattering in turbulent media. This will allow us to probe the turbulent properties of the circumburst medium, the host galaxy ISM/halo, and intervening halos along the path, as well as the IGM. Measurement of the Hubble constant and the dark energy parameter w can be made with FRBs, but require very large samples of localised FRBs (>103) to be effective on their own—they are best combined with other independent surveys to improve the constraints. Ionisation events, such as for He ii, leave a signature in the dispersion measure—redshift relation, and if FRBs exist prior to these times, they can be used to probe the reionisation era, although more than 103 localised FRBs are required.
14 citations
TL;DR: In this paper , the authors present a hydrodynamical modeling of a massive binary consisting of a magnetar and an early-type star, and apply the maser cyclotron mechanism of the radio emission generation to model spectral properties of the sources.
Abstract:
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, and the viewing angle. To describe properties of the known sources it is necessary to assume large eccentricities ≳ 0.5. We apply the maser cyclotron mechanism of the radio emission generation to model spectral properties of the sources. The produced spectrum is not wide: Δν/ν ∼ 0.2 and the typical frequency depends on the radius of the shock where the emission is generated. The shock radius changes along the orbit. This, together with changing parameters of the medium, allows us to explain the frequency drift during the phase of visibility. Frequency dependence of the degree of polarization at few GHz can be a consequence of a small scale turbulence in the shocked stellar wind. It is much more difficult to explain huge (∼105 [rad/m2]) and variable value of the rotation measure observed for FRB 121102. We suggest that this can be explained if the supernova explosion which produced the magnetar happened near a dense interstellar cloud with n ∼ 100 cm−3.
5 citations
TL;DR: In this paper , the authors used the first CHIME/FRB catalog to classify fast radio bursts (FRBs) into two classes: non-repeating and repeating FRBs.
Abstract: Although fast radio bursts (FRBs) have been an active field in astronomy and cosmology, their origin is still unknown to date. One of the interesting topics is the classification of FRBs, which is closely related to the origin of FRBs. Different physical mechanisms are required by different classes of FRBs. In the literature, they usually could be classified into non-repeating and repeating FRBs. Well motivated by the observations, here we are interested in the possible subclassification of FRBs. By using the first CHIME/FRB catalog, we propose to subclassify non-repeating (type I) FRBs into type Ia and Ib FRBs. The distribution of type Ia FRBs is delayed with respect to the cosmic star formation history (SFH), and hence they are probably associated with old stellar populations, while the distribution of type Ib FRBs tracks SFH, and hence they are probably associated with young stellar populations. Accordingly, the physical criteria for this subclassification of type I FRBs have been clearly determined. We find that there are some tight empirical correlations for type Ia FRBs but not for type Ib FRBs, and vice versa. These make them different in physical properties. Similarly, we suggest that repeating (type II) FRBs could also be subclassified into type IIa and IIb FRBs. A universal subclassification scheme is given at the end. This subclassification of FRBs might help us to reveal quite different physical mechanisms behind them, and improve their applications in astronomy and cosmology.
4 citations
References
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TL;DR: The Two Micron All Sky Survey (2MASS) as mentioned in this paper collected 25.4 Tbytes of raw imaging data from two dedicated 1.3 m diameter telescopes located at Mount Hopkins, Arizona and CerroTololo, Chile.
Abstract: Between 1997 June and 2001 February the Two Micron All Sky Survey (2MASS) collected 25.4 Tbytes of raw imagingdatacovering99.998%ofthecelestialsphereinthenear-infraredJ(1.25 � m),H(1.65 � m),andKs(2.16 � m) bandpasses. Observations were conducted from two dedicated 1.3 m diameter telescopes located at Mount Hopkins, Arizona,andCerroTololo,Chile.The7.8sofintegrationtimeaccumulatedforeachpointontheskyandstrictquality control yielded a 10 � point-source detection level of better than 15.8, 15.1, and 14.3 mag at the J, H, and Ks bands, respectively, for virtually the entire sky. Bright source extractions have 1 � photometric uncertainty of <0.03 mag and astrometric accuracy of order 100 mas. Calibration offsets between any two points in the sky are <0.02 mag. The 2MASS All-Sky Data Release includes 4.1 million compressed FITS images covering the entire sky, 471 million source extractions in a Point Source Catalog, and 1.6 million objects identified as extended in an Extended Source Catalog.
12,126 citations
TL;DR: In this article, it is argued that a convective dynamo can also generate a very strong dipole field after the merger of a neutron star binary, but only if the merged star survives for as long as about 10-100 ms.
Abstract: It is proposed that the main observational signature of magnetars, high-field neutron stars, is gamma-ray bursts powered by their vast reservoirs of magnetic energy. If they acquire large recoils, most magnetars are unbound from the Galaxy or reside in an extended, weakly bound Galactic corona. There is evidence that the soft gamma repeaters are young magnetars. It is argued that a convective dynamo can also generate a very strong dipole field after the merger of a neutron star binary, but only if the merged star survives for as long as about 10-100 ms. Several mechanisms which could impart a large recoil to these stars at birth, sufficient to escape from the Galactic disk, are discussed.
2,482 citations
01 Jan 2005
TL;DR: The Swift Gamma-Ray Explorer (XRT) as mentioned in this paper uses a mirror set built for JET-X and an XMM-Newton/EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of > 120 cm2 at 1.5 keV, field of view of 23.6 × 23. 6 arcminutes, and angular resolution of 18 arcseconds.
Abstract: he Swift Gamma-Ray Explorer is designed to make prompt multiwavelength observations of gamma-ray bursts (GRBs) and GRB afterglows. The X-ray telescope (XRT) enables Swift to determine GRB positions with a few arcseconds accuracy within 100 s of the burst onset. The XRT utilizes a mirror set built for JET-X and an XMM-Newton/EPIC MOS CCD detector to provide a sensitive broad-band (0.2–10 keV) X-ray imager with effective area of > 120 cm2 at 1.5 keV, field of view of 23.6 × 23.6 arcminutes, and angular resolution of 18 arcseconds (HPD). The detection sensitivity is 2×10−14 erg cm−2 s−1 in 104 s. The instrument is designed to provide automated source detection and position reporting within 5 s of target acquisition. It can also measure the redshifts of GRBs with Fe line emission or other spectral features. The XRT operates in an auto-exposure mode, adjusting the CCD readout mode automatically to optimize the science return for each frame as the source intensity fades. The XRT will measure spectra and lightcurves of the GRB afterglow beginning about a minute after the burst and will follow each burst for days or weeks.
2,253 citations
TL;DR: The Swift Gamma-Ray Explorer (XRT) as mentioned in this paper uses a mirror set built for JET-X and an XMM/EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of > 120 cm^2 at 1.5 keV, field of view of 23.6 x23.6 arcminutes, and angular resolution of 18 arcseconds (HPD).
Abstract: The Swift Gamma-Ray Explorer is designed to make prompt multiwavelength observations of Gamma-Ray Bursts (GRBs) and GRB afterglows. The X-ray Telescope (XRT) enables Swift to determine GRB positions with a few arcseconds accuracy within 100 seconds of the burst onset.
The XRT utilizes a mirror set built for JET-X and an XMM/EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of > 120 cm^2 at 1.5 keV, field of view of 23.6 x 23.6 arcminutes, and angular resolution of 18 arcseconds (HPD). The detection sensitivity is 2x10^-14 erg cm^-2 s^-1 in 10^4 seconds. The instrument is designed to provide automated source detection and position reporting within 5 seconds of target acquisition. It can also measure the redshifts of GRBs with Fe line emission or other spectral features. The XRT operates in an auto-exposure mode, adjusting the CCD readout mode automatically to optimize the science return for each frame as the source intensity fades. The XRT will measure spectra and lightcurves of the GRB afterglow beginning about a minute after the burst and will follow each burst for days or weeks.
2,104 citations
TL;DR: A 30-jansky dispersed burst, less than 5 milliseconds in duration, located 3° from the Small Magellanic Cloud is found, which implies that it was a singular event such as a supernova or coalescence of relativistic objects.
Abstract: Pulsar surveys offer a rare opportunity to monitor the radio sky for impulsive burst-like events with millisecond durations. We analyzed archival survey data and found a 30-jansky dispersed burst, less than 5 milliseconds in duration, located 3 degrees from the Small Magellanic Cloud. The burst properties argue against a physical association with our Galaxy or the Small Magellanic Cloud. Current models for the free electron content in the universe imply that the burst is less than 1 gigaparsec distant. No further bursts were seen in 90 hours of additional observations, which implies that it was a singular event such as a supernova or coalescence of relativistic objects. Hundreds of similar events could occur every day and, if detected, could serve as cosmological probes.
1,644 citations