Aims: The X-ray emission of massive stars has been studied when these objects are in their main-sequence phase, as well as in their Wolf-Rayet phase. However, the X-ray properties of the transitional Luminous Blue Variable (LBV) phase remain unknown. Methods: Using a dedicated but limited XMM survey as well as archival XMM and Chandra observations, we performed the first X-ray survey of LBVs: about half of the known LBVs or candidate LBVs are studied. Results: Apart from the well known X-ray sources eta Car and Cyg OB2 #12, four additional LBVs are detected in this survey, though some doubt remains on the association with the X-ray source for two of these. For the other LBVs, upper limits on the flux were derived, down to log[LX/LBOL]−9.4 for PCyg. This variety in the strength of the X-ray emission is discussed, with particular emphasis on the potential influence of binarity.
@article{arxiv.1111.6375,
title = {The first X-ray survey of Galactic Luminous Blue Variables},
author = {Yael Naze and Gregor Rauw and Damien Hutsemekers},
journal= {arXiv preprint arXiv:1111.6375},
year = {2012}
}