At UTC 2020-05-14-05:40:45.7 (2020-05-14.23664005), we found a fast radio burst as part of the ongoing search program (UTMOST), at the Molonglo telescope.

Molonglo is a 1.6 km long East-West array (Bailes et al 2017, PASA, 34, 45) and was operating in drift-scan mode with pointing centred on the meridian at the time of detection. Source localisation is excellent in Right Ascension (5 arcsec at 1-sigma) but poor in Declination (~1.2 deg at 1-sigma) (see Caleb et al 2017 MNRAS 468, 3746).

FRB200514 was found during a blind FRB search programme in real-time using an automated GPU-accelerated/machine learning-based pipeline. Unfortunately, raw voltages were not recorded and so we were unable to analyse the FRB at native time resolution.

The optimal dispersion measure (DM) that maximizes the signal-to-noise ratio is: 349.4 pc cm^-3. The DM estimate of NE2001 model is ~85.3 pc cm^-3, and YMW16 model is ~228.2 pc cm^-3 at this position, resulting in an intergalactic excess of ~193 pc cm^-3. The upper limit on the DM-inferred redshift is thus z ~ 0.18.

An early estimate (lower limit) of the event’s apparent fluence is ~11 Jy ms (corrected for attenuation of the primary beam in the RA direction, but not in the Dec direction), with a detection signal-to-noise ratio = 9.8.

The most likely position is RA = 07:01:00.55, DEC =-45:54:25.0, J2000, Galactic: Gl = 256.1140 deg, Gb = -17.5560 deg. The 95% confidence localisation arc is as follows: (RA, DEC) in (hours, deg).

A formula describing the localisation arc is:

RA = 7.016655 + 1.673513e-3*(DEC + 46.007086) – 4.428062e-05*(DEC + 46.007086)**2

where RA is in hours, Dec is in deg, and is valid in the range Dec= [-50.3,-41.7]

Follow-up observations of the FRB are encouraged.