It BeppoSAX monitoring of the ``anomalous'' X-ray pulsar 4U 0142+61} SAX monitoring of the ``anomalous'' X-ray pulsar 4U 0142+61
Abstract
The 8.7 s X-ray pulsar 4U 0142+61 was monitored by BeppoSAX between January 1997 and February 1998. This source belongs to the rapidly growing class of ``anomalous" X-ray pulsars (AXPs) which have pulse periods in the 6-12 s range and no plausible optical, infrared or radio counterparts. The BeppoSAX periods measurements show that 4U 0142+61 continues its spin-down at a nearly constant rate of Pdot ~ 2x10(-12) s s(-1) . The 0.5-10 keV pulse shape is double peaked. The phase-averaged spectrum can be described by a steep absorbed power-law (Gamma ~ 4) plus a blackbody with kT ~ 0.4 keV. 4U 0142+61 was also detected serendipitously in a March 1996 ROSATXTE observation pointed towards the nearby 1455 s X-ray pulsar RX J0146.9+6121. The timing analysis results are reported for this observation and the spin history of 4U 0142+61 since 1979 is discussed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1999
- Bibcode:
- 1999A&A...346..929I
- Keywords:
-
- STARS: EVOLUTION;
- STARS: NEUTRON;
- STARS: PULSARS: INDIVIDUAL: 4U 0142+61;
- X-RAYS: STARS