Galaxy from the 'teenage' universe reveals its water map for the 1st time

Illustration shows water molecules seen in a vapor cloud around a galaxy.
Illustration shows water molecules seen in a vapor cloud around a galaxy, infrared emissions form these molecules can help track the formation of stars and black holes (Image credit: NASA, ESA, J. Dalcanton (University of Washington), R. Foley (University of California - Santa Cruz); Image processing: G. Kober (NASA Goddard/Catholic University of America)/ Robert Lea)

For the first time, scientists managed to develop a map of water distribution in a galaxy that existed when the 13.8-billion-year-old universe was just a cosmic teenager.

The galaxy, designated J1135, is located around 12 billion light-years from Earth and is therefore seen as it was less than 2 billion years after the Big Bang

J1135's water map, created as part of a Scuola Internazionale Superiore di Studi Avanzati (SISSA) study conducted by the Galaxy Observational and Theoretical Astrophysics (GOThA) team, also has an unprecedented resolution that could reveal never-before-seen dynamics of early universe galaxies.

Though water is an essential ingredient for life, its presence across the universe has a purpose beyond searching for habitable regions. Scientists can use the distribution of water across a galaxy to tell the cosmic story of certain processes occurring within. This is because, as water changes its state from ice to vapor, it indicates areas of increased energy where stars, or even black holes, are being born. In short, that means finding water vapor in a particular region of a galaxy indicates that something very important is happening there. 

"Water can be found not only on Earth but anywhere in space, in different states," Francesca Perrotta, lead author of the study and a SISSA researcher, said in a statement. "For example, in the form of ice, water can be found in so-called molecular clouds, dense regions of dust and gas in which stars are born."

"Water acts like a cloak," Perrotta continued, "covering the surface of interstellar dust grains, which form the building blocks of these molecular clouds and the principal catalysts of molecule formation in space.”

Related: James Webb Space Telescope finds water in super-hot exoplanet's atmosphere

Perrotta also explained that there are times with something breaks the stillness and coldness of these molecular clouds, such as a star birth that releases heat or a black hole beginning to feast on surrounding matter that, in turn, emits energy.

Radiation from these disruptive sources heats frozen water, causing it to convert straight to a gaseous form, aka water vapor, during a process called sublimation. Then, as this water vapor cools, it emits infrared light that astronomers are able to observe.

"Astrophysicists can then observe this water vapor emission to map the regions of the galaxy where energy is produced, giving us unprecedented insights into how galaxies are formed," Perrotta said.

That emission data can also be combined with the mapping of certain molecules, such as carbon dioxide, to reveal even more about how galaxies come together over time. 

But observing early galaxies, such as J1135, wouldn’t be possible without a little help from a phenomenon first predicted in Albert Einstein’s theory of general relativity called "gravitational lensing."

A deep dive into early galaxies, courtesy of Einstein

Einstein's 1915 theory of general relativity basically predicts that objects with mass have a warping effect on the very fabric of space and time, assuming time as tangible in higher dimensions. This is akin to the 2D analogy of spherical weights placed on a stretched rubber sheet causing dents in the fabric. Just as weights with greater mass cause more extreme curving of the sheet, cosmic objects of greater mass cause more extreme warping of spacetime. Except, in reality, the warping of spacetime happens in 4D because of the time bit.

Not only does that curvature give rise to what we know as gravity, but also to a really interesting phenomena to do with light.

When light from a background source  —  say, an ancient star  —  passes by spacetime curvature created by a massive galaxy between that background source and Earth, the curve of the light's path past the intervening object depends on how close it comes to the warp. This ultimately means the light from the same object can arrive at our telescopes at different times.

As a result of this, not only can the same background object appear at multiple points in a single image, but can also be magnified by the effect, hence the description of these intervening objects as “gravitational lenses.”

The phenomenon has been used to great effect by the James Webb Space Telescope (JWST), as the instrument has observed the earliest galaxies ever seen by humanity. And, importantly for the new study, it was also integral in the discovery of J1135.

By playing a role in helping scientists determine the water distribution of J1135, gravitational lensing has also become integral in understanding how that galaxy evolved during the teenage years of the universe. A better picture of this transition will hopefully be revealed by the team as they continue to investigate this galaxy.

“It isn’t yet clear how galaxies are formed. There are at least two possible scenarios, not necessarily alternative: one sees the aggregation of small galaxies to create larger ones, and the other sees the formation of stars in situ,” Perrotta said. “Studies like ours help us to understand what is happening, specifically in that galaxy, but we can also potentially deduce more generic information from that.”

The team's research was published July 19 in The Astrophysical Journal.

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Robert Lea
Senior Writer

Robert Lea is a science journalist in the U.K. whose articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University. Follow him on Twitter @sciencef1rst.

  • rod
    The reference cited title, "The Way of Water: ALMA Resolves H2O Emission Lines in a Strongly Lensed Dusty Star-forming Galaxy at z ∼ 3.1",
    Good to know the z number used in this cosmology model interpretation. Using Ned Wright,
    "The age at redshift z was 2.094 Gyr.
    The light travel time was 11.628 Gyr.
    The comoving radial distance, which goes into Hubble's law, is 6578.5 Mpc or 21.456 Gly."

    The reported, "The galaxy, J1135, is located 12 billion light-years away and is seen as it was less than 2 billion years after the Big Bang."

    The comoving radial distance shows today it is more than 21 Gly from Earth and space expands some 1.5x c velocity for that distance.
  • magnoflux
    Creating the universe electrically is simple if you can produce huge equal amounts of positive and negative charges; but the trick is to keep them apart or they will annihilate each other.
    The next trick is how to combine not just positive ions surrounded by electrons but combine 2 hydrogen with 8 oxygen ions to form water which can now be seen in J1135 to have existed just after the big bang.