Search for radio pulsations in four Anomalous X-ray Pulsars and discovery of two new pulsars

Burgay M;Rea N;Israel GL;Possenti A;BURDERI, LUCIANO;Di Salvo T;D'AMICO, NICOLO';Stella L.

2006-01-01

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Abstract

We report on observations of four southern Anomalous X-ray Pulsars (1RXS J170849.0-400910, 1E 1048.1-5937, 1E 1841-045 and AXJ1845-0258) obtained at 1.4 GHz using the Parkes Radio Telescope. Radio pulsations from these sources have been searched (i) by directly folding the time-series at a number of trial periods centred on the value of the spin rate obtained from the X-ray observations; (ii) by performing a blind search and (iii) by using a code sensitive to single de-dispersed pulses, with the aim to detect signals similar to those of the recently discovered Rotating Radio Transients. No evidence for radio pulsations with an upper limit of similar to 0.1 mJy for any of the four targets has been found. The blind search led to the serendipitous discovery of two new pulsars, rotating with a spin period of about 0.7 s and 92 m s, respectively, and to the further detection of 18 known pulsars, two of which were also detected in the single-pulse search.