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A team of Australian researchers used two Mauna Kea-based observatories — Gemini North and the W.M. Keck Observatory — to discover why some galaxies are clumpy rather than spiral in shape, and it appears that low spin is to blame.
The finding challenges an earlier theory that high levels of gas cause clumpy galaxies, and sheds light on the conditions that brought about the birth of most of the stars in the universe. The finding was published last month in the Astrophysical Journal.
“This result was obtained by a unique and unusual combination of two large telescopes,” said Swinburne University astronomy professor Karl Glazebrook, co-author and leader of the survey team. “We used Keck adaptive optics to probe the fine details of galaxy rotation and Gemini to look at the large-scale distribution. This made possible a result that was not before known about the spin of early primitive galaxies.”
A combination of integral field spectroscopy data from the Keck and Gemini observatories was the key to obtaining measurements for a galaxy’s spin.
Lead author Danail Obreschkow, from the University of Western Australia node of the International Centre for Radio Astronomy Research, said that 10 billion years ago the universe was full of clumpy galaxies, but these developed into more regular objects as they evolved; the majority of stars in the sky today, including our 5 billion-year-old sun, were probably born inside these clumpy galaxies.
The research team focused on a few rare galaxies known as the DYNAMO galaxies, which still look clumpy even though they’re seen “only” 500 million years in the past.
