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ANI |
Updated: Apr 22, 2020, 9:08 AM IST
California [USA], April 22 (ANI): Results from a sky study program called ALPINE reveal that disk-shaped rotating galaxies may have existed in larger numbers earlier in the universe than previously thought.
The program, formally called ‘ALMA’s Large Program to Investigate C + in Early Years’, uses data obtained from 70 hours of sky observations with the ALMA (Atacama Large Millimeter / Submillimeter Matrix) observatory in Chile, in combination with data from previous observations by a host of other telescopes, including the WM Keck Observatory in Hawaii and NASA’s Hubble and Spitzer space telescopes.
Specifically, the survey looked at a sky patch containing dozens of remote galaxies.
“This is the first multi-wavelength study from ultraviolet to radio waves from distant galaxies that existed between 1 and 1.5 billion years after the Big Bang,” said Andreas Faisst, IPAC staff scientist and principal investigator. of the ALPINE program. , which includes scientists from around the world.
One of the key functions of ALPINE is to use ALMA to observe the signature of an ion known as C +, which is a positively charged form of carbon. When ultraviolet light from newborn stars hits clouds of dust, it creates the C + atoms.
By measuring the signature of this atom, or ’emission line’, in galaxies, astronomers can see how galaxies rotate; As the C + -containing gas in the galaxies rotates toward us, its light signature changes to bluer wavelengths, and as it rotates, the light changes to redder wavelengths.
This is similar to a police car siren that increases in pitch as it runs towards you and decreases as it drives away.
The ALPINE team performed C + measurements on 118 remote galaxies to create a catalog not only of their rotation speeds, but also of other characteristics such as the density of the gas and the number of stars that form.
The survey revealed rotating shattered galaxies that were in the process of merging, as well as apparently perfectly smooth spiral-shaped galaxies. About 15 percent of the observed galaxies had a smooth and orderly rotation expected for spiral galaxies.
However, the authors note, galaxies may not be spirals but rotating discs with groups of material. Future observations with the next generation of space telescopes will determine the detailed structure of these galaxies.
“We are finding very well-ordered rotating galaxies at this very early and rather turbulent stage in our universe. That means they must have formed through a smooth process of gas collection and have not yet collided with other galaxies, as many of the other galaxies have. had it, “Faisst said.
By combining the ALMA data with measurements from other telescopes, including the now retired Spitzer, which specifically helped measure the masses of galaxies, scientists are in a better position to study how these young galaxies evolve over time.
“How do galaxies grow so fast? What are the internal processes that allow them to grow so fast? These are questions that ALPINE is helping us answer. And with the upcoming launch of NASA’s James Webb Space Telescope, we can continue to these galaxies to learn even more, “said Faisst. (AND ME)
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