Hard X-ray detection from the core of the Monoceros R2 star forming region Original Research Article

We report on the hard X-ray detection from the core of the Monoceros R2 giant molecular cloud. The temperature is extremely high of about 5.5 keV in quiescent state. The strongest source among hard sources is associated with molecular core and suffered deep absorption. A hard X-ray flare near the core is also observed. The temperature is also extremely high. Strong Ca and Fe lines are observed in flare spectrum, and the energies are significantly lower than those of usual plasma model. The flare spectrum show some differences from those of low-mass young stars. It might be evidence of the X-rays from a high-mass protostar.