Identify and Study Outflows in Ultraluminous X-Ray Source M33 X-8

Ultraluminous X-ray source (ULX) M33 X-8 is near the boundary of the ultraluminous classification, making it an important source for understanding the link between typical extragalactic X-ray binaries and ultraluminous X-ray pulsars (ULXPs). The number of such unique ULXP sources currently known is only 8. Powerful outflows of moderately ionized gas at mildly relativistic velocities have been found in three systems: NGC 1313 X-1, NGC 5408 X-1 and NGC 55 ULX. High resolution spectra would firmly establish that M33 X-8 contains a pulsar by its wind outflow and cyclotron line. We propose 92 ks exposure time to study and identify M33 X-8.