Hyerin Cho

TL;DR: In this article, the authors reported the detection of a fast radio burst (FRB 181112), localized with arcsecond precision, that passes through the halo of a foreground galaxy.

TL;DR: In this article, the authors reported the detection of a fast radio burst (FRB 181112) with arcsecond precision, which passes through the halo of a foreground galaxy.

Abstract: We have developed a new coherent dedispersion mode to study the emission of Fast Radio Bursts that trigger the voltage capture capability of the Australian SKA Pathfinder (ASKAP) interferometer. In principle the mode can probe emission timescales down to 3 ns with full polarimetric information preserved. Enabled by the new capability, here we present a spectropolarimetric analysis of FRB 181112 detected by ASKAP, localized to a galaxy at redshift 0.47. At microsecond time resolution the burst is resolved into four narrow pulses with a rise time of just $15 \mu$s for the brightest. The pulses have a diversity of morphology, but do not show evidence for temporal broadening by turbulent plasma along the line of sight, nor is there any evidence for periodicity in their arrival times. The pulses are highly polarized (up to 95%), with the polarization position angle varying both between and within pulses. The pulses have apparent rotation measures that vary by $15\pm 2\, {\rm rad \,m^{-2}}$ and apparent dispersion measures that vary by $0.041\pm 0.004\,{\rm pc\,cm^{-3}}$. Conversion between linear and circular polarization is observed across the brightest pulse. We conclude that the FRB 181112 pulses are most consistent with being a direct manifestation of the emission process or the result of propagation through a relativistic plasma close to the source. This demonstrates that our method, which facilitates high-time-resolution polarimetric observations of FRBs, can be used to study not only burst emission processes, but also a diversity of propagation effects present on the gigaparsec paths they traverse.

TL;DR: In this paper, a fast radio burst (FRB) at 920 MHz was discovered during commensal observations conducted with the Australian Square Kilometre Array Pathfinder (ASKAP) as part of the Commensal Real-time ASKAP Fast Transients (CRAFT) survey.

TL;DR: In this paper, the authors investigated the implications of lensing of FRBs for the detectability of compact dark matter by FRBs and found that a sample size of ∼130 FRBs would be required to constrain compact dark mass to less than the existing 35% detection probability with 95% confidence.