scholarly journals A single fast radio burst localized to a massive galaxy at cosmological distance

Science ◽  
2019 ◽  
Vol 365 (6453) ◽  
pp. 565-570 ◽  
Author(s):  
K. W. Bannister ◽  
A. T. Deller ◽  
C. Phillips ◽  
J.-P. Macquart ◽  
J. X. Prochaska ◽  
...  
Keyword(s):  
Column Density ◽  
Single Pulse ◽  
Line Of Sight ◽  
Host Galaxy ◽  
Radio Bursts ◽  
Positional Accuracy ◽  
Radio Emissions ◽  
Individual Host ◽  
Fast Radio Burst ◽  
Massive Galaxy

Fast radio bursts (FRBs) are brief radio emissions from distant astronomical sources. Some are known to repeat, but most are single bursts. Nonrepeating FRB observations have had insufficient positional accuracy to localize them to an individual host galaxy. We report the interferometric localization of the single-pulse FRB 180924 to a position 4 kiloparsecs from the center of a luminous galaxy at redshift 0.3214. The burst has not been observed to repeat. The properties of the burst and its host are markedly different from those of the only other accurately localized FRB source. The integrated electron column density along the line of sight closely matches models of the intergalactic medium, indicating that some FRBs are clean probes of the baryonic component of the cosmic web.

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 A fast radio burst source at a complex magnetised site in a barred galaxy

2021 ◽  
Author(s):  
K.J. Lee ◽  
Heng Xu ◽  
J.R. Niu ◽  
P. Chen ◽  
Weiwei Zhu ◽  
...  
Keyword(s):  
Optical Observations ◽  
Host Galaxy ◽  
Radio Bursts ◽  
Radio Waves ◽  
Galactocentric Distance ◽  
Burst Source ◽  
Radiation Mechanism ◽  
Circular Polarisation ◽  
Rotation Measure ◽  
Fast Radio Burst

Abstract Fast radio bursts (FRBs) are highly dispersed radio bursts prevailing in the universe. The recent detection of FRB~200428 from a Galactic magnetar suggested that at least some FRBs originate from magnetars, but it is unclear whether the majority of cosmological FRBs, especially the actively repeating ones, are produced from the magnetar channel. Here we report the detection of 1863 polarised bursts from the repeating source FRB~20201124A during a dedicated radio observational campaign of Five-hundred-meter Aperture Spherical radio Telescope (FAST). The large sample of radio bursts detected in 88 hr over 54 days indicate a significant, irregular, short-time variation of the Faraday rotation measure (RM) of the source during the first 36 days, followed by a constant RM during the later 18 days. Significant circular polarisation up to 75\% was observed in a good fraction of bursts. Evidence suggests that some low-level circular polarisation originates from the conversion from linear polarisation during the propagation of the radio waves, but an intrinsic radiation mechanism is required to produce the higher degree of circular polarisation. All of these features provide evidence for a more complicated, dynamically evolving, magnetised immediate environment around this FRB source. Its host galaxy was previously known. Our optical observations reveal that it is a Milky-Way-sized, metal-rich, barred-spiral galaxy at redshift z=0.09795+-0.00003, with the FRB residing in a low stellar density, interarm region at an intermediate galactocentric distance, an environment not directly expected for a young magnetar formed during an extreme explosion of a massive star.

scholarly journals Astrometric accuracy of snapshot fast radio burst localisations with ASKAP

2021 ◽  
Vol 38 ◽  
Author(s):  
Cherie K. Day ◽  
Adam T. Deller ◽  
Clancy W. James ◽  
Emil Lenc ◽  
Shivani Bhandari ◽  
...  
Keyword(s):  
Reasonable Agreement ◽  
Signal To Noise Ratio ◽  
Host Galaxy ◽  
Radio Sources ◽  
Radio Bursts ◽  
Signal To Noise ◽  
Relative Separation ◽  
Fast Transients ◽  
Fast Radio Burst ◽  
Host Properties

Abstract The recent increase in well-localised fast radio bursts (FRBs) has facilitated in-depth studies of global FRB host properties, the source circumburst medium, and the potential impacts of these environments on the burst properties. The Australian Square Kilometre Array Pathfinder (ASKAP) has localised 11 FRBs with sub-arcsecond to arcsecond precision, leading to sub-galaxy localisation regions in some cases and those covering much of the host galaxy in others. The method used to astrometrically register the FRB image frame for ASKAP, in order to align it with images taken at other wavelengths, is currently limited by the brightness of continuum sources detected in the short-duration (‘snapshot’) voltage data captured by the Commensal Real-Time ASKAP Fast Transients (CRAFT) software correlator, which are used to correct for any frame offsets due to imperfect calibration solutions and estimate the accuracy of any required correction. In this paper, we use dedicated observations of bright, compact radio sources in the low- and mid-frequency bands observable by ASKAP to investigate the typical astrometric accuracy of the positions obtained using this so-called ‘snapshot’ technique. Having captured these data with both the CRAFT software and ASKAP hardware correlators, we also compare the offset distributions obtained from both data products to estimate a typical offset between the image frames resulting from the differing processing paths, laying the groundwork for future use of the longer duration, higher signal-to-noise ratio (S/N) data recorded by the hardware correlator. We find typical offsets between the two frames of ${\sim}0.6$ and ${\sim}0.3$ arcsec in the low- and mid-band data, respectively, for both RA and Dec. We also find reasonable agreement between our offset distributions and those of the published FRBs. We detect only a weak dependence in positional offset on the relative separation in time and elevation between target and calibrator scans, with the trends being more pronounced in the low-band data and in Dec. Conversely, the offsets show a clear dependence on frequency in the low band, which we compare to the frequency-dependent Dec. offsets found in FRB 200430. In addition, we present a refined methodology for estimating the overall astrometric accuracy of CRAFT FRBs.

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 Fast radio burst dispersion measures and rotation measures and the origin of intergalactic magnetic fields

2019 ◽  
Vol 488 (3) ◽  
pp. 4220-4238 ◽  
Author(s):  
S Hackstein ◽  
M Brüggen ◽  
F Vazza ◽  
B M Gaensler ◽  
V Heesen
Keyword(s):  
Magnetic Fields ◽  
Radio Burst ◽  
Milky Way ◽  
Intergalactic Medium ◽  
Local Environment ◽  
Distribution Functions ◽  
Host Galaxy ◽  
Radio Bursts ◽  
Dispersion Measures ◽  
Fast Radio Burst

ABSTRACT We investigate the possibility of measuring intergalactic magnetic fields using the dispersion measures and rotation measures of fast radio bursts. With Bayesian methods, we produce probability density functions for values of these measures. We distinguish between contributions from the intergalactic medium, the host galaxy, and the local environment of the progenitor. To this end, we use constrained, magnetohydrodynamic simulations of the local Universe to compute lines-of-sight integrals from the position of the Milky Way. In particular, we differentiate between predominantly astrophysical and primordial origins of magnetic fields in the intergalactic medium. We test different possible types of host galaxies and probe different distribution functions of fast radio burst progenitor locations inside the host galaxy. Under the assumption that fast radio bursts are produced by magnetars, we use analytic predictions to account for the contribution of the local environment. We find that less than 100 fast radio bursts from magnetars in stellar-wind environments hosted by starburst dwarf galaxies at redshift z ≳ 0.5 suffice to discriminate between predominantly primordial and astrophysical origins of intergalactic magnetic fields. However, this requires the contribution of the Milky Way to be removed with a precision of ≈1 rad m−2. We show the potential existence of a subset of fast radio bursts whose rotation measures carry information on the strength of the intergalactic magnetic field and its origins.

scholarly journals Exploring galaxy dark matter haloes across redshifts with strong quasar absorbers

2019 ◽  
Vol 489 (2) ◽  
pp. 2270-2279 ◽  
Author(s):  
L Christensen ◽  
P Møller ◽  
N H P Rhodin ◽  
K E Heintz ◽  
J P U Fynbo
Keyword(s):  
Dark Matter ◽  
Velocity Ratio ◽  
Dark Matter Halo ◽  
Line Of Sight ◽  
Host Galaxy ◽  
Host Galaxies ◽  
Mass Distributions ◽  
Line Widths ◽  
Stellar Masses ◽  
Massive Galaxy

Abstract Quasar lines of sight intersect intervening galaxy discs or circumgalactic environments at random impact parameters and potential well depths. Absorption line velocity widths (Δv90) are known to scale with host galaxy stellar masses, and inversely with the projected separation from the quasar line of sight. Its dependence on stellar mass can be eliminated by normalizing with the emission-line widths of the host galaxies, σem, so that absorbers with a range of Δv90 values can be compared directly. Using a sample of DLA systems at 0.2 <z < 3.2 with spectroscopically confirmed host galaxies, we find that the velocity ratio Δv90/σem decreases with projected distances from the hosts. We compare the data with expectations of line-of-sight velocity dispersions derived for different dark matter halo mass distributions, and find that models with steeper radial dark matter profiles provide a better fit to the observations, although the scatter remains large. Gas outflows from the galaxies may cause an increased scatter, or scale radii of dark matter halo models may not be representative for the galaxies. We demonstrate by computing virial velocities, that metal-rich DLAs that belong to massive galaxy haloes (Mhalo ≈ 1012 M⊙) mostly remain gravitationally bound to the haloes.

scholarly journals Non-detection of fast radio bursts from six gamma-ray burst remnants with possible magnetar engines

2019 ◽  
Vol 489 (3) ◽  
pp. 3643-3647 ◽  
Author(s):  
Yunpeng Men ◽  
Kshitij Aggarwal ◽  
Ye Li ◽  
Divya Palaniswamy ◽  
Sarah Burke-Spolaor ◽  
...  
Keyword(s):  
Detection Probability ◽  
Luminosity Function ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Host Galaxy ◽  
Radio Bursts ◽  
Left Behind ◽  
Central Engine ◽  
Fast Radio Burst ◽  
Green Bank Telescope

ABSTRACT The analogy of the host galaxy of the repeating fast radio burst (FRB) source FRB 121102 and those of long gamma-ray bursts (GRBs) and superluminous supernovae (SLSNe) has led to the suggestion that young magnetars born in GRBs and SLSNe could be the central engine of repeating FRBs. We test such a hypothesis by performing dedicated observations of the remnants of six GRBs with evidence of having a magnetar central engine using the Arecibo telescope and the Robert C. Byrd Green Bank Telescope (GBT). A total of ∼20 h of observations of these sources did not detect any FRB from these remnants. Under the assumptions that all these GRBs left behind a long-lived magnetar and that the bursting rate of FRB 121102 is typical for a magnetar FRB engine, we estimate a non-detection probability of 8.9 × 10−6. Even though these non-detections cannot exclude the young magnetar model of FRBs, we place constraints on the burst rate and luminosity function of FRBs from these GRB targets.

scholarly journals A population analysis of pulse broadening in ASKAP fast radio bursts

2020 ◽  
Vol 497 (2) ◽  
pp. 1382-1390 ◽  
Author(s):  
Hao Qiu ◽  
Ryan M Shannon ◽  
Wael Farah ◽  
Jean-Pierre Macquart ◽  
Adam T Deller ◽  
...  
Keyword(s):  
Population Analysis ◽  
Inhomogeneous Plasma ◽  
Line Of Sight ◽  
Host Galaxy ◽  
Dispersion Measure ◽  
High Time Resolution ◽  
Radio Bursts ◽  
Width Distribution ◽  
Millisecond Time Scale ◽  
Pulse Broadening

ABSTRACT The pulse morphology of fast radio bursts (FRBs) provides key information in both understanding progenitor physics and the plasma medium through which the burst propagates. We present a study of the profiles of 33 bright FRBs detected by the Australian Square Kilometre Array Pathfinder. We identify seven FRBs with measureable intrinsic pulse widths, including two FRBs that have been seen to repeat. In our modest sample, we see no evidence for bimodality in the pulse width distribution. We also identify five FRBs with evidence of millisecond time-scale pulse broadening caused by scattering in inhomogeneous plasma. We find no evidence for a relationship between pulse broadening and extragalactic dispersion measure. The scattering could be either caused by extreme turbulence in the host galaxy or chance propagation through foreground galaxies. With future high time resolution observations and detailed study of host galaxy properties, we may be able to probe line-of-sight turbulence on gigaparsec scales.

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.

Dust-reddened Quasars

1996 ◽  
Vol 13 (2) ◽  
pp. 183-184 ◽  
Author(s):  
M. J. Drinkwater ◽  
R. L. Webster ◽  
P. J. Francis ◽  
T. Wiklind ◽  
F. Combes
Keyword(s):  
Molecular Clouds ◽  
Physical State ◽  
Absorption Lines ◽  
Line Of Sight ◽  
Host Galaxy ◽  
Molecular Gas ◽  
Molecular Absorption

We have recently discovered evidence for a population of radio-loud quasars that is reddened by dust. The dust is either along the line of sight to the quasars or is associated with the quasars. In the latter case the dust may be in molecular clouds in the quasar’s host galaxy, or in a molecular torus around the nucleus. We are planning to use 3 mm observations to search for molecular absorption lines (CO and HCO+) associated with dust at the redshift of these quasars. If any absorption systems are detected we will be able to deduce detailed information about the physical state of the molecular gas, hopefully showing which of the proposed locations of the dust is most likely.

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