Astronomers at Newcastle University and Colby College have developed a new technique to determine how likely it is that two galaxies are very close together and are expected to collide in the future. They’ve applied this method to hundreds of thousands of galaxies in the distant Universe in an attempt to better understand the so-called cosmic noon, a time when most of the Universe’s galaxy and black hole growth is expected to have taken place.
Supermassive black holes grow by accreting gas that falls on to them. However, what drives the gas close enough to the black holes for this to happen is an ongoing mystery.
One possibility is that when galaxies are close enough together, they are likely to be gravitationally pulled towards each other and merge into one larger galaxy.
In the final stages of its journey into a black hole, gas lights up and produces a huge amount of energy. This energy is typically detected using visible light or X-rays.
However, Newcastle University astronomer Chris Harrison and colleagues were only able to detect the growing black holes using infrared light.
They analyzed data from many different telescopes, including the NASA/ESA Hubble Space Telescope and NASA’s Spitzer Space Telescope.
They developed a new technique to determine how likely it is that two galaxies are very close together and are expected to collide in the future.
They applied this new method to hundreds of thousands of galaxies in the distant Universe (looking at galaxies formed 2 to 6 billion years after the Big Bang) in an attempt to better understand the so-called cosmic noon.
Understanding how black holes grew during this time is fundamental in modern day galactic research, especially as it may give us an insight into the supermassive black hole situated inside the Milky Way, and how our galaxy evolved over time.
As they are so far away, only a small number of cosmic noon galaxies meet the required criteria to get precise measurements of their…
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