From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link
From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link
In recent work with high-resolution grating spectrometers (RGS) aboard XMM-Newton Pinto et al. (2016) have discovered that two bright and archetypal ultraluminous X-ray sources (ULXs) have strong relativistic winds in agreement with theoretical predictions of high accretion rates. It has been proposed that such winds can become optically thick enough …