[ Previous | Next ]
ATEL # 903; Marta Burgay (INAF-OAC), Nanda Rea (SRON), Gianluca Israel (INAF-OAR), Andrea Possenti (INAF-OAC)
on 30 Sep 2006; 14:33 UT
Password Certification: Nanda Rea (N.Rea@sron.nl)
Subjects: Radio, Neutron Stars, Pulsars, Transients
The Anomalous X-ray Pulsar CXO J167410.2-455216 (ATEL #893, #894, #896,#901, #902) has been observed on 2006 September 21st to emit an X-ray burst, which rapidly triggered the Burst Alert Telescope on Swift (Krimm et al. GCN #5581). Pre and post burst X-ray monitoring with XMM-Newton, Swift and Chandra showed that the source apparently initiated an outburst state. Triggered by the detection of a radio outburst following the X-ray transient activity of the AXP XTE J1810-197, we started an observation program of CXO J167410.2-455216 with the Parkes radio antenna.
The source has been observed on the 28 of September 2006 (MJD 54006.203) for 4 hrs at a frequency of 1400 MHz. The total 256 MHz bandwidth was split into 512 channels, each 0.5 MHz wide, and the time series was 1 bit sampled every 0.2 ms. Data have been searched for periodicity around the value obtained from the X-ray observations closest to the radio pointing (Atel 901) over a wide range of dispersion measure values (DM < 2000).
No radio pulsation with a period matching (within +/-1 ms) the X-ray period (i.e. between 10.60969 and 10.61169), nor half of it, has been found. The upper limit on the radio pulsations flux density at 1400 MHz is 0.04 mJy. A blind search of the data resulted in the serendipitous discovery of a previously unknown pulsar with a period P~431 ms and DM~1050, which we believe not associated with the AXP.
Next Parkes observation is planned for October 2.
We would like to thank John Reynolds for having promptly accorded us these observations in his Discretionary Director's Time. The Parkes radio telescope is part of the Australia Telescope, which is funded by the Commonwealth Government for operation as a National Facility managed by CSIRO.