Astronomers have spotted the second most distant dusty, starburst galaxy ever found in the Universe. The find is reported this week in the journal Nature Astronomy by Dr. Jorge Zavala, a postdoctoral research fellow at the University of Texas at Austin, and colleagues.
Color composite image of HATLAS J090045.4+004125 (also known as G09 83808): the blue channel represents data from the Sloan Digital Sky Survey and the red channel the data collected by the Atacama Large Millimeter/submillimeter Array. Image credit: Zavala et al, doi: 10.1038/s41550-017-0297-8.
The newly-discovered galaxy, called HATLAS J090045.4+004125, lies a whopping 12.8 billion light-years from Earth.
A massive galaxy between astronomers on Earth and HATLAS J090045.4+004125 acted as a giant magnifying glass and made it look about 10 times brighter and closer than it is.
“The Big Bang happened 13.7 billion years ago, and now we are seeing this galaxy from 12.8 billion years ago, so it was forming within the first billion years after the Big Bang,” said co-author Dr. Min Yun, from the University of Massachusetts.
“Seeing an object within the first billion years is remarkable because the Universe was fully ionized, that is, it was too hot and too uniform to form anything for the first 400 million years.”
“So our best guess is that the first stars and galaxies and black holes all formed within the first half a billion to one billion years.”
“HATLAS J090045.4+004125 is very close to being one of the first galaxies ever to form.”
The astronomers found the ancient galaxy using the Large Millimeter Telescope (LMT), which is operated jointly by the University of Massachusetts Amherst and Mexico’s Instituto Nacional de Astrofísica, Óptica y Electrónica.
“This galaxy is the oldest object ever detected by the LMT,” Dr. Yun said.
“At present there is only one other, slightly older and more distant object like this known.”
“This result is not a surprise, because this is what the LMT was built to do, but we are very excited.”
These high redshift, very distant objects are a class of mythical beasts in astrophysics.
“We always knew there were some out there that are enormously large and bright, but they are invisible in visible light spectrum because they are so obscured by the thick dust clouds that surround their young stars,” Dr. Yun said.
“Paradoxically, the most prolific star-forming galaxies and thus the most luminous are also the most difficult to study using traditional optical telescopes like the NASA/ESA Hubble Space Telescope because they are also the most obscured by dust.”
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Jorge A. Zavala et al. A dusty star-forming galaxy at z = 6 revealed by strong gravitational lensing. Nature Astronomy, published online November 6, 2017; doi: 10.1038/s41550-017-0297-8
