ASCA observations of GRO J1744-28

We report the ASCA results of the bursting X-ray pulsar GRO J1744-28, which was observed in 1996 February and 1997 March. The source flux in the 2-10 keV band was 2.0 x 10(-8) ergs s(-1) cm(2) in 1996 and 5.0 x 10(-9) ergs s( -1) cm2 in 1997. We detected 12 and 17 type II bursts during type two obser vations, with mean bursting intervals of about 27 min and 37 min. Each burs t is followed by an intensity dip with the depleted flux depending on the b urst fluence. The energy spectra are approximated by an absorbed power law with additional structure around 6-7 keV. The constant absorption column, ( 5-6) x 10(22) cm(-2), independent of the observation dates and emission pha ses (persistent, burst, and dir) is interpreted as an interstellar absorpti on. The source may be actually located near the Galactic center, at a dista nce of 8.5 kpc. The structure in the energy spectrum at 6 7 keV is most pro bably due to iron and may be reproduced by a disk line model with additiona l broadening mechanism.