The host galaxy of a fast radio burst

Abstract

In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.

Burst Astrophysics

“…It is important to note that according to WUM the relative energy density of the Intergalactic plasma is 4.8% that is in a very good agreement with experimentally found value 4.9% ± 1.3% [33]. The developed analysis based on WUM is consistent with all experimental results obtained by authors of [33].…”

“…On 18 April 2015, FRB 150418 was detected by the Parkes observatory and within hours, several telescopes including the Australia Telescope Compact Array caught an "afterglow" of the flash, which took six days to fade [20]. The Subaru telescope was used to find what was thought to be the host galaxy and determine its redshift and the implied distance to the burst [21].…”

Large Host-galaxy Dispersion Measure of Fast Radio Bursts

“…Fast radio bursts (FRBs) are mysterious astronomical radio transients with short intrinsic durations (∼ 1ms), large dispersion measures (DM 200 pc cm −3 ), and an all-sky distribution (Lorimer et al 2007; Keane et al 2012Keane et al , 2016Thornton et al 2013;Burke-Spolaor & Bannister 2014;Spitler et al 2014Spitler et al , 2016Masui et al 2015;Petroff et al 2015;Ravi et al 2015Ravi et al , 2016Champion et al 2016;Chatterjee et al 2017;Caleb et al 2017). Recently, thanks to the precise localization and multi-wavelength follow-up observations of the repeating source FRB 121102 (Chatterjee et al 2017;Marcote et al 2017;Tendulkar et al 2017), the distance scale of FRBs has been finally settled to a cosmological scale at z = 0.19273 (Tendulkar et al 2017).…”

Search for transient gravitational waves in coincidence with short-duration radio transients during 2007–2013

“…In the final moments before the compact objects merge, the upward sweep in frequency of the gravitational wave emission is predicted to produce a characteristic chirp-like signal. Recent evidence suggests that neutron star binary mergers may create at least some fraction of FRBs [34].…”

“…[19,27,34,38]), with indications that at least a subset of radio bursts may be coupled with gamma-ray bursts. We therefore follow previous LIGO analyses [6] and calculate 90% confidence level exclusion distances, for two of our simulated circularly polarized waveforms, assuming an optimistic standard siren in which ∼1% of a solar mass is converted to gravitational wave energy.…”