A new eclipsing low-mass X-ray binary with a giant companion

作者：Maeda Yoshitomo^*; Mori Hideyuki; Dotani Tadayasu

来源：Advances in Space Research, 2013, 51(7): 1278-1281.

DOI：10.1016/j.asr.2012.11.005

• Low mass X-ray binary
• Eclipsing
• ASTROSAT

We detected hard X-ray emission from the unidentified Galactic bulge source 1RXS J175721.2-304405 with ASCA. The observed absorption column, flux and power-law index led us to consider that 1RXS J175721.2-304405 may be a new low-mass X-ray binary located near the Galactic center. Furthermore, the X-ray light-curve shows a step-function-like time variability, which is likely due to the occultation of a companion star. Future follow-up observations by missions such as ASTROSAT may reveal a periodic eclipse from 1RXS J175721.2-304405 if it is covered long enough. Since the long orbital period suggests a giant companion, follow-up observations will give firm evidence that 1RXS J175721.2-304405 is a new and rare eclipsing low-mass X-ray binary with a giant companion.

• 出版日期2013-4-1