Ancient, massive galaxies that haunt the dusty reaches of our universe have been hiding, invisible to the eyes of the famous Hubble Space Telescope. But now astronomers aiming at infrared data have discovered 39 of them – lurking in strange places from the early universe where (and when) the night sky would look very different from our own.
If you were to approach one of these long-scale galaxies while inside a spaceship, it would probably be at least recognizable to you: stars you could see with the naked eye, swirling dust, a large black hole in the middle. And if you were to appear in any way today, it would probably look completely different than more than 11
It is because these distant galaxies, like most distant things in our universe, are moving away from us – a consequence of dark energy driving space. As Live Science has previously reported, light extends from objects that move away from us to longer, redder wavelengths. And these super-distant galaxies are rushing so fast, according to the researchers who discovered them, that the ultraviolet and visible light they released has completely moved into the long "submillimeter" wavelength range that even Hubble cannot detect. [15 Unforgettable Images of Stars]
As a result, the researchers wrote in a paper published August 7 in the journal Nature, most astronomers focused on the first 2 billion years of the universe have stopped studying odd orbits: galaxies very far away that are still mobile enough relative to Earth that Hubble can see them. But these non-offset galaxies are probably not the norm.
"This raises the questions about the real abundance of massive galaxies and the degree of star formation in the early universe," the researchers wrote. In other words, how many galaxies were there, and how fast did they make stars?
Astronomers have previously seen individual massive galaxies from the deep past, the researchers wrote, as well as smaller galaxies that tend to be shrouded in dust. But for this work, the team used a series of submillimeter-sensitive telescopes to detect these 39 previously invisible ancient galaxies.
(Image credit: Wang et al.)
"It was difficult to convince our peers that these galaxies were as old as we suspected they were. Our first suspicions about their existence came from Spitzer Space Telescope & # 39; s infrared data, "said Tao Wang, chief paper and astronomer at the University of Tokyo, in a statement." But [the Atacama Large Millimeter/submillimeter Array in Chile] has sharp eyes and revealed details at submillimeter wavelengths , the best wavelength for peeking through dust found in the early universe. Nevertheless, it took additional data from the imaginatively named Very Large Telescope in Chile to really prove that we saw ancient massive galaxies that no one had seen before. "
And these findings are important for early universe models and for explaining how our modern universe came to exist.
" Such a large abundance of massive and dusty galaxies early in the Universe challenges our understanding of massive galaxy formation, "the researchers wrote in [9 Most Intriguing Earth-Like Planets]
Several different existing models predict a much lower density of these types of galaxies, though researchers have long suspected that some would be out. With this new discovery, researchers must go back and refine their models to account for this new set of previously invisible things.
These galaxies, the researchers wrote, are probably part of the group that gave rise to modern massive galaxies. But they had much more dust and were much denser than the Milky Way galaxy.
"The night sky seemed much more majestic. The bigger stars mean there would be many more stars in the vicinity of appearing bigger and brighter, "Wang said in the statement." Conversely, the large amount of dust means that farther away stars would be much less visible, so the background to these bright near stars can be a big dark void. "
Originally published on Live Science .