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Israel et al. report on simultaneous radio and X-ray observations
of the radio-emitting magnetar 1E 1547.0– 5408 made with the 64-m
Parkes radio telescope and the Chandra and XMM-Newton X-ray
observatories. The magnetar was observed in a period of intense X-ray
bursting activity and enhanced X-ray emission, and Israel et
al. report the detection of two radio bursts from 1E 1547.0–5408
reminiscent of Fast Radio Bursts (FRBs). One of the radio bursts was
anticipated by ∼1 s (about half a rotation period of the pulsar) by a
bright SGR-like X-ray burst. Radio pulsations were not detected
during the observation showing the FRB-like radio bursts, while they
were detected in the previous radio observation. The figure above
shows X-ray and radio simultaneous observations of 1E 1547.0–5408
performed around the time of the brightest X-ray burst and the two
radio pulses (pulse A and B). The blue line is the X-ray burst
lightcurve, while the grey line is the X-ray folded light curve, with
a period of 2.07 seconds, from XMM-Newton data. The simultaneous
Parkes radio light curve is shown in red. The grey shaded areas are
the phase intervals of the expected peak of the radio pulse profiles
extrapolated from previous Parkes observations. Note that the flat top
of the first radio peak, and the drop of the intensity of the radio
signal below the average noise level following both pulses, are
artifacts caused by the saturation of the backend. The two radio
bursts are neither aligned with the expected radio pulsations nor with
the peak of the X-ray pulse profile. Comparing the luminosity of these
FRB-like bursts and those reported from SGR 1935+2154, Israel et
al. find that the wide range in radio efficiency and/or luminosity of
magnetar bursts in the Galaxy may bridge the gap between “ordinary”
pulsar radio bursts and the extragalactic FRB phenomenon.
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