This Black Hole Mass Problem is Confusing Physicists

Black holes are a popular historical and contemporary field of research across many areas of physics from astronomy to particle physics, quantum mechanics, and general relativity. In the Universe, we observe two distributions of Black Holes. 1) is the stellar mass black holes; those which result when a star dies either through direct core collapse, or by forming a neutron star which then further collapses after accreting gas from a companion red giant star. The tend to range from a few times the mass of our sun, to up to one hundred times. 2) are the supermassive black holes which seed themselves at the centres of every galaxy. These have masses upwards of one hundred thousand solar masses, and grow throughout cosmic time as they accrete gas and dust from the inner dynamically complex regions of their host galaxy. They then drive several mechanisms including shocking radio jets as well as highly ionised biconical outflows of gas (winds), capable of blowing galactic debris out of the galaxy and into the intergalactic medium. These active galactic nuclei (AGN) are able to influence the star formation and thus evolution of the galaxy as a whole, despite the black hole and accretion disk size being less than that of the solar system. However, we detect no black holes with masses between these two distributions - which goes against theories suggesting how black holes should form, merge, and grow at the centres of galaxies early in the age of the Universe. This is an active problem in astrophysics, with current and future experiments poised to attempt to resolve it. This includes detecting distant galaxies with the James Webb Space Telescope (JWST), which can then have their potential black hole spheres of influence resolved spatially with the planned higher resolution Extremely Large Telescope (ELT). Or doing something similar through gravitational wave detection with the LIGO interferometer, before higher sensitivity experiment with LISA, potentially capable of detecting these missing intermediate mass black holes. 0:00 - The Missing Intermediate Mass Black Hole Problem in Physics 1:03 - Low mass end; Stellar mass black holes 2:47 - High mass end; Supermassive black holes and AGN 4:04 - Telescope Observations and Cosmological Simulations 5:16 - Where are the Intermediate Mass Black Holes? 8:57 - Future Experiments with the ELT, and with Gravitational Waves