RXTEObservations of 1A 1744−361: Correlated Spectral and Timing Behavior

We analyze Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array(PCA) data of the transient low mass X-ray binary (LMXB) system 1A 1744-361. Weexplore the X-ray intensity and spectral evolution of the source, performtiming analysis, and find that 1A 1744-361 shows `atoll' behavior during theoutbursts. The color-color diagram indicates that this LMXB was observed in alow intensity spectrally hard (low-hard) state and in a high intensity `banana'state. The low-hard state shows a horizontal pattern in the color-colordiagram, and the previously reported `dipper QPO' appears only during thisstate. We also perform energy spectral analyses, and report the first detectionof broad iron emission line and iron absorption edge from 1A 1744-361.Comment: 20 pages, 4 tables, 4 figures, accepted for publication in Ap