Water could have been abundant in the first billion years

Water could have been abundant in the first billion years
This Hubble image features dark knots of gas and dust known as "Bok globules," which are dense pockets in larger molecular clouds. Similar islands of material in the early universe could have held as much water vapor as we find in our galaxy today, despite containing a thousand times less oxygen. Credit: NASA, ESA, and The Hubble Heritage Team

How soon after the Big Bang could water have existed? Not right away, because water molecules contain oxygen and oxygen had to be formed in the first stars. Then that oxygen had to disperse and unite with hydrogen in significant amounts. New theoretical work finds that despite these complications, water vapor could have been just as abundant in pockets of space a billion years after the Big Bang as it is today.

"We looked at the chemistry within young containing a thousand times less than our Sun. To our surprise, we found we can get as much water vapor as we see in our own galaxy," says astrophysicist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA).

The early universe lacked elements heavier than hydrogen and helium. The first generation of stars are believed to have been massive and short-lived. Those stars generated elements like oxygen, which then spread outward via stellar winds and supernova explosions. This resulted in "islands" of gas enriched in heavy elements. Even these islands, however, were much poorer in oxygen than gas within the Milky Way today.

The team examined the chemical reactions that could lead to the formation of water within the oxygen-poor environment of early molecular clouds. They found that at temperatures around 80 degrees Fahrenheit (300 Kelvin), abundant water could form in the despite the relative lack of raw materials.

"These temperatures are likely because the universe then was warmer than today and the gas was unable to cool effectively," explains lead author and PhD student Shmuel Bialy of Tel Aviv University.

"The glow of the cosmic microwave background was hotter, and gas densities were higher," adds Amiel Sternberg, a co-author from Tel Aviv University.

Although ultraviolet light from stars would break apart , after hundreds of millions of years an equilibrium could be reached between water formation and destruction. The team found that equilibrium to be similar to levels of seen in the local universe.

"You can build up significant quantities of water in the gas phase even without much enrichment in ," adds Bialy.

This current work calculates how much water could exist in the gas phase within molecular clouds that will form later generations of stars and planets. It doesn't address how much water would exist in ice form (which dominates within our galaxy) or what fraction of all the water might actually be incorporated into newly forming planetary systems.

This work has been accepted for publication in the Astrophysical Journal Letters and is available online.


Explore further

Chemical fingerprints of ancient supernovae found

Journal information: Astrophysical Journal Letters

Citation: Water could have been abundant in the first billion years (2015, April 28) retrieved 18 August 2019 from https://phys.org/news/2015-04-abundant-billion-years.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
482 shares

Feedback to editors

User comments

Apr 28, 2015
oxygen had to be formed in the first stars.


This could be a faulty assumption.

If anything, the polar nature of water seems to be a good mechanism for assisting in the formation of new stars, brown dwarfs, and planets by causing other molecules to clump together.

Apr 29, 2015
There was no Big Bang. Now go revise your theory.

Apr 29, 2015
oxygen had to be formed in the first stars.


This could be a faulty assumption.


This ought to be a good one. Okayeei Skippy, I'll nibble at the bait. Why you think that is a faulty assuming? The oxygen had to come from somewhere before he can join up with the hydrogen to make the water. Where do you assume he came from?

Apr 29, 2015
This ought to be a good one. Okayeei Skippy, I'll nibble at the bait. Why you think that is a faulty assuming? The oxygen had to come from somewhere before he can join up with the hydrogen to make the water. Where do you assume he came from?


The hydrogen and helium had to come from somewhere too, Gilligan.

Apr 29, 2015
This ought to be a good one. Okayeei Skippy, I'll nibble at the bait. Why you think that is a faulty assuming? The oxygen had to come from somewhere before he can join up with the hydrogen to make the water. Where do you assume he came from?


The hydrogen and helium had to come from somewhere too, Gilligan.


Yeah, but they came first before the stars. Then the stars use them to make all the other stuffs. At least that is what all the professional (without the mental conditions) Skippys tell me.

I am not a scientist-Skippy like you are not either, so it is hard for me to explain good. But if you want I can recommend the really good book that explains it so even you and ol Ira-Skippy can understand it.

May 02, 2015
Yeah, but they came first before the stars. Then the stars use them to make all the other stuffs. At least that is what all the professional (without the mental conditions) Skippys tell me.

I am not a scientist-Skippy like you are not either, so it is hard for me to explain good. But if you want I can recommend the really good book that explains it so even you and ol Ira-Skippy can understand it.


I've read the books you fool.

I've read them for years and years, and they don't have anything that forbids creation of heavier elements for any reason that isn't arbitrary.

May 03, 2015
Nice result, not completely unexpected seeing how the earliest planets are about that old but a nice test of the current cosmology.

@RTG, Returners, Ren: "no Big Bang", "simple question", "anything that forbids ... for any reason that isn't arbitrary".

As per above, this strengthens the current cosmology, since it is yet another successful test: no tension between observations and earlier validated theory.

Specifically:

- I wouldn't call the question simple, since there is so much detail. But the answer is simple, as it is inflation that resulted in a on large scales uniform and homogeneous universe. You don't really need math to see that, just look at the measured CMB maps and see for yourself that the universe energy content is isotropic and homogeneous to 1/100 000th parts (check the scale axis, ~ 400 uK vs the ~ 3 K average !): http://en.wikiped...4096.png

[tbctd]

May 03, 2015
[ctd]

[ctd]

- The forbidding constraint is nucleosynthesis, which is a result of Cold Inflation (dilution of any preexisting inhomogeneities and matter) and Hot Big Bang (heats the universe and results in the de novo particles that we observe). [ http://en.wikiped...ynthesis ] The latest Planck results nail these constraints.

It isn't foolish to suggest reading when obviously it hasn't been done or the individual (who has wasted "years and years" reading them) does not understand their contents. An individual may belong to, or emulate, an all too common group that suits the common definition of "fool": http://en.wikiped...r_effect .

[I'm just leaving this here, because it is nigh impossible to remotely diagnose individuals on a background of statistics for populations - which is why doctors aren't allowed to. The link discusses easy remedies, FWIW.]

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more