Transient radio bursts from rotating neutron stars.
The radio sky is relatively unexplored for transient signals, although the potential of radio-transient searches is high. This was demonstrated recently by the discovery of a previously unknown type of source, varying on timescales of minutes to hours. Here we report a search for radio sources that vary on much shorter timescales. We found eleven objects characterized by single, dispersed bursts having durations between 2 and 30 ms. The average time intervals between bursts range from 4 min to 3 h with radio emission typically detectable for <1 s per day. From an analysis of the burst arrival times, we have identified periodicities in the range 0.4-7 s for ten of the eleven sources, suggesting origins in rotating neutron stars. Despite the small number of sources detected at present, their ephemeral nature implies a total Galactic population significantly exceeding that of the regularly pulsing radio pulsars. Five of the ten sources have periods >4 s, and the rate of change of the pulse period has been measured for three of them; for one source, we have inferred a high magnetic field strength of 5 x 10(13) G. This suggests that the new population is related to other classes of isolated neutron stars observed at X-ray and gamma-ray wavelengths.
McLaughlin
M A
MA
Jodrell Bank Observatory, University of Manchester, Macclesfield, Cheshire SK11 9DL, UK. Maura.McLaughlin@manchester.ac.uk
Lyne
A G
AG
Lorimer
D R
DR
Kramer
M
M
Faulkner
A J
AJ
Manchester
R N
RN
Cordes
J M
JM
Camilo
F
F
Possenti
A
A
Stairs
I H
IH
Hobbs
G
G
D'Amico
N
N
Burgay
M
M
O'Brien
J T
JT