Confirmation of six Be X-ray binaries in the Small Magellanic Cloud

The X-ray binary population of the Small Magellanic Cloud (SMC) contains a large number of massive X-ray binaries, and the recent survey of the SMC by XMM-Newton has resulted in almost 50 more tentative high-mass X-ray binary (HMXB) candidates. Using probability parameters from Haberl and Sturm together with the optical spectra and timing in this work, we confirm six new massive X-ray binaries in the SMC. We also report two very probable binary periods of 36.4 d in XMM 1859 and of 72.2 d in XMM 2300. These Be X-ray binaries are likely part of the general SMC population, which rarely undergoes an X-ray outburst.