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takyon [soylentnews.org] writes:

Early Star Formation Presents New Cosmic Mystery [skyandtelescope.com]

New observations suggest that stars began forming just 250 million years after the Big Bang — a record-breaker that will likely open a new line of cosmological inquiry.

Astronomers peering back into time suggest that the cosmic dark ages — before the universe hosted its sea of twinkling lights — might have lasted no more than 250 million years. The team presented their results in the journal Nature [nature.com] [DOI: 10.1038/s41586-018-0117-z] [DX [doi.org]] today.

Takuya Hashimoto (Osaka Sangyo University, Japan) and his colleagues used the Atacama Large Millimeter/submillimeter Array (ALMA) to peer at a galaxy whose light was emitted 550 million years after the big bang, picking up a long-sought signal: oxygen. It's the most distant galaxy for which astronomers have been able to detect individual elements — and that single element has a big story to tell.

Because only hydrogen, helium, and a little lithium emerged from the Big Bang, the young universe was pristine. It wasn't until the first generation of stars exploded, breathing carbon, oxygen and other heavy elements into the cosmos, that the universe's inventory of elements increased. So, the detection of oxygen 550 million years after the Big Bang suggests that a generation of stars had already formed and died by this point.

Also at the National Radio Astronomy Observatory [nrao.edu].

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