Discovery of a 7 second X-ray pulsar, AX J1845.0-0300

We report here a serendipitous discovery of a faint X-ray pulsar, AX J1845.0-0300, with ASCA. Its period of similar to 7 s, together with its low luminosity and the soft spectrum, suggest that it may be the eighth candidate member of braking X-ray pulsars. Two observations, 3.5 yr apart, showed a significant flux decrease of more than 1 order of magnitude. The source is in the Scutum arm region (l similar to 30 degrees), which was claimed as a colony of X-ray pulsars by Koyama et al. This discovery strengthens the hypothesis by Koyama et al. that there may be a number of low-luminosity pulsars on the Galactic plane, particularly in the Scutum arm region.