By definition, a black hole is the end result of the death of a star as it collapses upon itself and consumes all of the gas, dust, light and anything else within its grasp. When you combine the time it takes for a star to be born, grow, die and become a black hole, the process takes billions of years. That’s why astronomers have been puzzled by a strange black hole that existed in a galaxy from the early days of the universe – less than a billion years after the Big Bang. How did it form so fast? A new study may have the explanation.
According to the Monthly Notices of the Royal Astronomical Society, astronomers at the University of Texas at Austin found anomalies indicating a possible black hole in the remote CR7 galaxy discovered in 2015. CR7 is believed to be 13 billion years old and formed 800 million years after the Big Bang. At that age, the astronomers believe it was a creator of first-generation stars.
So how did this early galaxy end up with a black hole? Enter the concept of the “direct collapse black hole.” The what?
It’s a cosmic miracle. It’s the only time in the history of the universe when conditions are just right” for them to form.
UT Austin astronomer Volker Bromm and Avi Loeb of the Harvard-Smithsonian Center for Astrophysics, theorized the existence of a supermassive seed black hole that could skip the star birth-death cycle and go directly to black hole. Here’s Bromm’s recipe:
[You begin with a] primordial cloud of hydrogen and helium, suffused in a sea of ultraviolet radiation. You crunch this cloud in the gravitational field of a dark-matter halo. Normally, the cloud would be able to cool, and fragment to form stars. However, the ultraviolet photons keep the gas hot, thus suppressing any star formation. These are the desired, near-miraculous conditions: collapse without fragmentation! As the gas gets more and more compact, eventually you have the conditions for a massive black hole.
Using the Stampede supercomputer at UT Austin’s Texas Advanced Computing Center, astronomer Aaron Smith confirmed Bromm’s direct collapse black hole recipe using a new, computer-power-sucking model called “radiation hydrodynamics.” The model’s success convinced NASA to offer two more possible direct-collapse black holes discovered at the Chandra X-ray Observatory and astronomer Dr. David Sobral of Lancaster University says his team has identified four more early galaxies with the same characteristics as CR7.
Direct collapse black holes don’t need a star to form. They’re like the reality TV of black holes.