Abstract: While ultraluminous supersoft X-ray sources (ULSs) bear features for intermediate mass black holes or very massive white dwarfs possibly close to Chandrasekhar mass limit, our recent discovery of processing relativistic baryonic jets from a prototype ULS in M81 demonstrate that they are not IMBHs or WDs, but black holes accreting at super-Eddington rates. This discovery strengthens the recent ideas that ULXs are stellar black holes with supercritical accretion, and provides a vivid manifestation of what happens when a black hole devours too much, that is, it will generate thick disk winds and fire out sub-relativistic baryonic jets along the funnel as predicted by recent numerical simulations.

Bio: Dr. Jifeng Liu obtained his B.A degree from Beijing University and his Ph.D. degree from University of Michigan, and went on to Harvard University as a postdoc. He was a Chandra fellow (renamed Einstein fellow now) between 2006 and 2009, and became an astrophysicist at Harvard afterward. Jifeng is now based in Beijing as a Principal astronomer at National Astronomical Observatories of China, and as a chair professor at School of Astronomy and Space Sciences at University of Chinese Academy of Sciences, with research interests mainly in multi-wavelength observations of compact objects in the Milky Way and nearby galaxies.