Detection of FRB181228 at the Molonglo Radio Telescope

ATel #12335; W. Farah (Swinburne University of Technology "SUT"), M. Bailes (SUT), A. Jameson (SUT), C. Flynn (SUT), V. Gupta (SUT), T. Bateman (The University of Sydney "USyd"), E. D. Barr (Max-Planck-Institut fuer Radioastronomie "MPIfR"), S. Bhandari (CSIRO/ATNF), M. Caleb (University of Manchester), D. Campbell-Wilson (USyd), C. Day (SUT), A. Deller (SUT), A. J. Green (USyd), R. W. Hunstead (USyd), F. Jankowski (University of Manchester), E. F. Keane (Square Kilometer Array Organisation), M. E. Lower (SUT), S. Oslowski (SUT), A. Parthasarathy (SUT), K. Plant (Caltech), D. C. Price (SUT), V. Ravi (Harvard-Smithsonian Center for Astrophysics), R. M. Shannon (SUT), A. Sutherland (USyd), D. Temby (USyd), G. Torr (USyd), G. Urquhart (USyd), V. Venkatraman Krishnan (MPIfR)
on 28 Dec 2018; 16:03 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Wael Farah (wfarah@swin.edu.au)

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At UTC 2018-12-28-13:48:50.1 (2018-12-28.5755799), we found a bright 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).

FRB181228 was found during a blind FRB search programme in real-time using an automated GPU-accelerated/machine learning based pipeline and the raw voltages were recorded for offline processing.

The optimal dispersion measure (DM) that maximizes the signal-to-noise ratio is: 354 pc cm^-3. The DM estimate of NE2001 model is ~58 pc cm^-3, and YMW16 model is ~61 pc cm^-3 at this position, resulting in an intergalactic excess of ~290 pc cm^-3. The upper limit on the DM-inferred redshift is thus z ~ 0.26.

An early estimate (lower limit) of the apparent fluence of the event is ~ 18 Jy ms (corrected for attenuation of the primary beam in the RA direction, but not in the Dec direction), width ~ 2.19 ms, with a detection signal-to-noise ratio = 12.

The most likely position is RA = 06:09:54.5, DEC = -45:59:00, J2000, Galactic: Gl = 253.3915 deg, Gb = -26.0633 deg. The 95% confidence localisation arc is as follows: (RA, DEC) in (hours, deg)

6.152928 -48.822722
6.153536 -48.321778
6.154128 -47.820833
6.154706 -47.319889
6.155267 -46.818972
6.155814 -46.318028
6.156344 -45.817083
6.156864 -45.316139
6.157369 -44.815167
6.157861 -44.314222
6.158342 -43.813278
6.158808 -43.312333
6.159264 -42.811389

A formula describing the localisation arc is:
RA = 6.016988 - 4.092281e-3*(DEC - 45.967341) - 2.804353e-05*(DEC - 45.967341)**2
where RA is in hours, Dec is in deg, and is valid in the Dec range [-50.3,-41.6]

For the dispersion sweep, and the localisation plots, follow this link

Follow-up observations of the FRBs are encouraged.

FRB181228