1 INTRODUCTION
2 SPECTROSCOPIC OBSERVATIONS
2.1 VLT/VIMOS
2.2 VLT/FORS2
2.3 VLT/X-shooter
2.4 SOAR/Goodman High Throughput spectrograph
2.5 Blanco/Hydra
2.6 GTC/OSIRIS
3 OPTICAL PHOTOMETRIC OBSERVATIONS
4 X-RAY OBSERVATIONS
4.1 CXB12
4.2 CXB34
4.3 Improved X-ray source positions
5 DISCUSSION
5.1 Individual sources
5.2 Active single and binary stars
6 SUMMARY