【天文学】高速電波バーストの母銀河が同定される

The location, host galaxy and redshift for a fast radio burst (FRB) are identified for the first time in a paper published in this week's Nature. The study provides new evidence for the origins of these enigmatic radio flashes from deep space and suggests that they fall into at least two different classes.

FRBs are bursts of radio waves that last only a few milliseconds. They possibly originate in distant galaxies; however, there is no generally accepted explanation for how they are created. Redshift measurement would allow astronomers to determine from how far away the FRB originated, but the difficulty in pinpointing the celestial coordinates of a burst before it disappears has precluded determining the redshift of any FRB to date.

Using the Parkes radio telescope in Australia, Evan Keane and colleagues report the discovery of FRB 150418. They found that FRB 150418 originated in an elliptical galaxy with a redshift of 0.492.No FRB has previously had its location and host galaxy identified, or its redshift precisely determined, the authors note. They suggest that because FRB 150418 took 6 days to fade, it is unlikely that the burst originated from a pulsar, which challenges the interpretation from another recently discovered radio burst. The findings suggest there are at least two classes of fast radio burst.