Discovery of a slow X-ray pulsator, AX J1740.1-2847, in the galactic center region

We report the discovery of an X-ray pulsar: AX J1740.1-2847, from the Galac tic center region. This source was found as a faint hard X-ray object on 19 98 September 7-8 with the ASCA Galactic center survey observation. Then, co herent pulsations of P = 729 +/- 14 s period were detected. The X-ray spect rum is described by a flat power-law of similar to 0.7 photon index. The la rge absorption column of log N-H similar to 22.4 cm(-2) indicates that AX J 1740.1-2847 is a distant source, larger than 2.4 kpc, and possibly near to the Galactic center region. The luminosity in the 2-10 keV band is larger t han 2.5x10(33) erg s(-1), or likely to be 3.2 x 10(34) erg s(-1) at the Gal actic-center distance. Although the slow-pulse period does not discriminate whether AX J1740.1-2847 is a white dwarf or neutron-star binary, the flat power-law and moderate luminosity strongly favor a neutron-star binary.