First — a bit of a primer on the graphic at right: In the top portion, at the far right, a small box identifies GN-z11 in a field of galaxies. The middle box shows a zoomed-in image of the galaxy. The box at the far left displays a map of the helium gas in the halo of GN-z11, including a clump that does not appear in the infrared colors shown in the middle panel. In the lower half of the graphic, a spectrum shows the distinct “fingerprint” of helium in the halo. The full spectrum shows no evidence of other elements and so suggests that the helium clump must be fairly pristine, made of hydrogen and helium gas left over from the big bang, without much contamination from heavier elements produced by stars. It is a complex topic, thus a complex graphic from the JWST team.

What it sets out is fairly simple, though: the first galaxies after the big bang have long been assumed to have been almost exclusively made of helium and hydrogen. Those, it was assumed, then collapsed, and re-ignited to form the complex multi-element galaxies like our modern Milky Way. But no observational proof existed for those Type II galaxies. Until now.

The new next gen space ‘scope has identified GN-z11, one of the oldest ever observed — and it is surrounded by an almost pure helium halo. That observation of infrared spectra is almost certainly from under 200 million years after the big bang. Here’s the full NASA / ESA story, and a bit of it:

…[Researchers have verified a pristine] gaseous clump of helium in the halo surrounding GN-z11 [one of the farthest, and thus oldest galaxies ever observed].

“The fact that we don’t see anything else beyond helium suggests that this clump must be fairly pristine,” said Maiolino. “This is something that was expected by theory and simulations in the vicinity of particularly massive galaxies from these epochs — that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters.”

Finding the never-before-seen Population III stars — the first generation of stars formed almost entirely from hydrogen and helium — is one of the most important goals of modern astrophysics. These stars are anticipated to be very massive, very luminous, and very hot. Their expected signature is the presence of ionized helium and the absence of chemical elements heavier than helium.

The formation of the first stars and galaxies marks a fundamental shift in cosmic history, during which the universe evolved from a dark and relatively simple state into the highly structured and complex environment we see today….

Bit by bit, we are unraveling the darkly mysterious fabric of our earliest epochs, deep at the edge of the known universe. What a time to be… alive! Onward… with baby girls here later this afternoon — grin.

नमस्ते