19th of April 2021 |
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ASKAP localisation of a repeating FRB source |
by Kumar et al. |
Hot on the heels of the ASKAP detection of a Fast Radio Burst from a
repeating FRB source, discovered with the Canadian CHIME telescope,
Kumar et al. reported the
ASKAP detection of a second Fast Radio Burst (FRB) coincident with the
FRB20201124A source. The burst, FRB 20210402A, was detected with a
reported signal to noise ratio of 13.4 in the incoherent sum of 23
antennas. The system was operating in a higher band than the first
FRB, with a central frequency of 1271.5 MHz, an observing bandwidth of
336 MHz, and a time resolution of 1.2 ms. Both ASKAP-detected bursts
were very bright, and with flux concentrated at the lower end of both
bands.
When ASKAP detected bursts, voltage data from buffers from individual antennas are triggered and downloaded. Day et al. used this technique to determine an interferometric localisation of the burst to the best-fit position (epoch J2000): RA: 05:08:03.662 DEC: +26:03:39.82, spatially coincident with a galaxy cataloged in the Sloan Digital Sky Survey photometric survey, SDSS J050803.48+260338.0. The galaxy has a catalogued photometric redshift of z=0.08+/-0.02 but based on the ASKAP localisation, Kilpatrick et al. initiated observations of the host galaxy of FRB20201124A with the Binospec optical spectrograph at the MMT Observatory in Arizona, detecting several emission lines at a common redshift of z=0.098+/-0.002. |