Role of triatomic H ion (H3+) in early star formation

[marcus]

H₃⁺

The original mothercloud was mostly H₂ and He. It didn't have molecular species containing C, N, and O that are good at radiating away heat they pick up by jostling each other when the cloud contracts.

So it was hard for the early clouds to contract by their own gravity, because they lacked effective means of shedding the surplus energy by radiating it away.

This positive ion (three protons and two electrons) is believed to have played a key role.
It is a good radiator. So naturally people want to LOOK FOR THE LIGHT it would have radiated in early universe clouds--appropriately redshifted during the intervening years of course.

So this group Pavanello et al ran a computer model of H₃⁺ and found its vibration modes and energy levels and what wavelengths of light to look for.
http://theop11.chem.elte.hu/main_index_files/2012_Pavanello_PRL.108.023002_H3p.pdf
They published their results in 13 January 2012 Physical Review Letters

There is also this press release blurb from the U of Arizona--containing some confused or misleading stuff but still of value as a popularization.
http://uanews.org/node/46088
http://www.astrobio.net/pressrelease/4695/the-molecule-that-made-the-universe

Later after the first generation of stars had "cooked" heavier elements like C, N, and O and burped them forth, the way stars do by various means, the clouds had an easier time contracting. Because they had good radiator molecules in them to help get rid of surplus energy as they contracted. So the subsequent generations of stars had an easier time forming, and this triatomic hydrogen ion would no longer have played such a key role.

 

[Almsco]

That's an interesting question! It seems like the H3+ molecule played a key role in the contracting of early universe clouds and the formation of the first stars. This is because it was able to effectively radiate away heat when the clouds contracted, due to its molecular structure which contained three protons and two electrons. Later on, after heavy elements such as C, N, and O had been produced by the first generation of stars, the clouds had an easier time contracting and the H3+ molecule wouldn't have been as essential.