Extraordinarily Hot X-ray Emission from the 09 Emission Line Star HD 119682

摘要

We present new optical and X-ray observations to show that the X-ray source 1WGA J1346.5--6255 previously associated with the SNR G309.2--0.6 can beunequivocally identified with the emission line star HD 119682 located in theforeground open cluster NGC 5281. Images from Chandra in the X-ray band as wellas from Magellan in the narrow optical H-alpha band show a coincidence of thesource positions within 0.5". The X-ray source appears extremely hot for anOB-star identified as of O9.7e type. XMM-Newton spectra show plasmatemperatures of 1 keV and >8 keV with an X-ray luminosity of 6.2E32 +/-0.1E32erg/s. The optical and X-ray properties are very reminiscent of the prototypeemission line star Gamma-Cas. We discuss the ramifications of this similaritywith respect to very early type emission line stars as a new class of hardX-ray sources.