We report the serendipitous discovery of a 7-s X-ray pulsar using data acquired with the Advanced Satellite for Cosmology and Astrophysics (ASCA). The pulsar is detected as an unresolved source located towards a region of the Galactic plane ( l,b ⋍ 29.5,0.08) that coincides with an overdensity of star-formation tracers. The signal suffers tremendous foreground absorption, equivalent to N H ⋍ 10 23 cm -2; the absorption correlates well with a line-of-sight that is tangential to the inner spiral arms and the 4-kpc molecular ring. The pulsar is not associated with any known supernova remnants or other cataloged objects in that direction. The near sinusoidal pulse (period P ⋍ 6.9712) is modulated at 35% pulsed amplitude, and the steep spectrum is characteristic of hot black-body emission with temperature kT ∼ 0.65 keV. We characterize the source as an anomalous X-ray pulsar (AXP).
- Pub Date:
- July 1998
- PULSARS: GENERAL;
- PULSARS: INDIVIDUAL: AX J1845-0258;
- X-RAYS: GENERAL;
- SUPERNOVA REMNANTS;
- 8 pages, latex, 4 figures, Accepted for publication in New Astronomy