Rossi X-Ray Timing Explorer Observations of the Anomalous Pulsar 4U 0142+61
Abstract
We observed the anomalous X-ray pulsar 4U 0142+61 using the Proportional Counter Array on board the Rossi X-Ray Timing Explorer in 1996 March. The pulse frequency was measured as ν=0.11510039(3) Hz, with an upper limit of |ν˙|<=4×10-13 Hz s-1 on the short-term change in frequency over the 4.6 day span of the observations. A compilation of all historical measurements showed an overall spin-down trend with slope ν˙=-3.0+/-0.1×10-14 Hz s-1. Searches for orbital modulations in pulse arrival times yielded an upper limit of axsini<~ 0.26 lt-s (99% confidence) for the period range 70 s to 2.5 days. These limits combined with previous optical limits and evolutionary arguments suggest that 4U 0142+61 is probably not a member of a binary system.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1999
- DOI:
- 10.1086/306839
- arXiv:
- arXiv:astro-ph/9809016
- Bibcode:
- 1999ApJ...513..464W
- Keywords:
-
- PULSARS: INDIVIDUAL (4U 0142+61);
- STARS: NEUTRON;
- X-RAYS: STARS;
- pulsars: individual (4U 0142+61);
- Stars: Neutron;
- X-Rays: Stars;
- Astrophysics
- E-Print:
- 20 pages (LaTeX) including 7 figures. Accepted for publication in the Astrophysical Journal