The host galaxy of a fast radio burst

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Clik here to view.© Image credit D. Kaplan (UWM), E. F. Keane (SKAO)

A real-time fast radio burst discovered at the Parkes telescope has led to the first identification of a host galaxy and redshift for these mysterious sources. Fast radio bursts (FRBs) are bright, millisecond radio pulses of unknown origin believed to come from outside our Galaxy. The large uncertainty in the sky position of all previously published FRBs makes pinpointing a host galaxy difficult, so no burst to-date has an accurate redshift measurement.

FRB 150418 was detected less than 10 seconds after it occurred by the SUrvey for Pulsars and Extragalactic Radio Bursts (SUPERB). Follow-up with the Australia Telescope Compact Array identified a fading radio transient lasting ~6 days in the field of the burst. From the precise location of the fading source a host galaxy was found with redshift z = 0.492 ± 0.008. The fading afterglow suggests a cataclysmic origin for FRB 150418 and the timescale of the radio transient is roughly consistent with the radio afterglow of a short gamma-ray burst.

The image shows an optical image of the field with the full-width half-maximum of the 13 Parkes beams superimposed as white circles. Insets show subsequent zooms of the field and the highly dispersed pulse of the burst arriving at a range of frequencies across the Parkes bandwidth over ~1 second.

The results are published in Nature this week.