SXP 323 - an unusual X-ray binary system in the Small Magellanic Cloud

Abstract

Spectroscopic observations taken with the VLT/UVES telescope/instrument are presented of the unusual Small Magellanic Cloud (SMC) X-ray binary system SXP 323 = AX J0051-733. This system shows a clear modulation at 0.71d in long term optical photometry which has been proposed as the binary period of this system. The high resolution optical spectra, taken at a range of phases during the 0.71d cycle, rule out this possibility. Instead it is suggested that this long-term effect is due to Non Radial Pulsations (NRP) in the Be star companion to SXP 323. In addition, the spectra show clear evidence for major changes in the (V/R) ratio of the double peaks of the Balmer lines indicative of asymmetries in the circumstellar disk. The complex structure of the interstellar lines are also discussed in the context of the SMC structure.

Accepted in MNRAS

References in corpus (6)

• A natural explanation for periodic X-ray outbursts in Be/X-ray binaries
• Optical properties of SMC X-ray binaries
• An Atlas of FUSE Sight Lines Toward the Magellanic Clouds
• OGLE observations of four X-ray binary pulsars in the SMC
• Observations of the unusual counterpart to the X-ray pulsar AX J0051-733
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Cited by in corpus (4)

• The Chandra survey of the SMC "Bar": II. Optical counterparts of X-ray sources
• Criteria for Dynamical Timescale Mass Transfer of Metal-poor Intermediate-mass Stars
• Photometric Periodicities of Be/X-ray Pulsars in the Small Magellanic Cloud
• Non-radial pulsations in the Be/X binaries 4U0115+63 and SAXJ2103.5+4545