“For something to collapse, not all systems have to shut down. In most cases, just one system is enough.” -Robert Kiyosaki
Do supermassive black holes form from the merger and growth of many smaller black holes, falling towards a cluster/galactic center where they find one another and grow into a behemoth? Or is there a direct-collapse mechanism at play, where a black hole thousands, tens of thousands or even hundreds of thousands of times the mass of our Sun forms spontaneously?
The X-ray and optical images of a small galaxy containing a black hole many tens of thousands of times the mass of our Sun. These black holes may have arisen first in the Universe by the direct collapse of matter. Image credit: X-ray: NASA/CXC/Univ of Michigan/V.F.Baldassare, et al; Optical: SDSS; Illustration: NASA/CXC/M.Weiss.
Until recently, this direct-collapse black hole scenario was thought to leave no observational signatures, but a pristine population of stars, discovered last year, shows a fast-moving offset between hydrogen and helium emissions and an ionization front over 50,000 light years across.
The starburst galaxy Henize 2-10, located 30 million light years away. Image credit: X-ray (NASA/CXC/Virginia/A.Reines et al); Radio (NRAO/AUI/NSF); Optical (NASA/STScI).
If high-resolution radio observations see ...