James Webb Space Telescope uncovers starbirth clues at 'cosmic noon' for 33,000 young stars

[Admin]

The latest image clicked by James Webb Space Telescope sheds light on how early stars formed during cosmic noon — more than 10 billion years ago.

James Webb Space Telescope uncovers starbirth clues at 'cosmic noon' for 33,000 young stars : Read more

 

[rod]

Impressive image of NGC 346 by JWST in the article. I read the 17-page PDF report cited.

ref - Discovery of dusty sub-solar mass young stellar objects in NGC 346 with JWST/NIRCam, https://arxiv.org/pdf/2301.03932.pdf, 11-Jan-2023.

My observation. From the 17-page PDF report: “1 Introduction Located in the Small Magellanic Cloud (SMC) at a distance of ~ 62 kpc [1], NGC 346 is a prominent young cluster (~ 3 Myr; [2]) actively forming stars. It is the brightest and largest star-formation region in this metal-poor galaxy (~ 1/5 Zsun; [3]) which has a comparable metallicity to galaxies at the epoch of peak star formation [“cosmic noon"; 4, 5]. Below these levels of chemical enrichment, the dust content of the interstellar medium (ISM) drops precipitously, altering the environment in which stars form (e.g., [6, 7]) … “NGC 346 is one of the most active star-forming regions in the Local Group. Its proximity, size (~ 100 x 100 pc^2), low foreground extinction, and an abundance of wide-field, high-resolution panchromatic data make it an ideal system for the study of both low- and high-mass star formation, the effects of this star formation on the surrounding medium, and the potential triggers of star formation in an environment vastly different from our local Galactic surroundings, and akin to galaxies at cosmic noon.”

My note. NGC 346 is close with a distance of about 62 kpc or about 202,000 light-years. The cluster compared to star formation at z ~ 3.0 (cosmic noon) in the BB model, the universe could be some 2 Gyr old after BB event (and comoving radial distance indicates 4D space expanding faster than c velocity) compared to present. During cosmic noon in the BB model, much higher and faster star formation rates than the present we see in our galaxy. NGC 346 is about 3 Myr too. Considerable interpretation is needed and extrapolations when making star formation comparisons using “cosmic noon” and NGC 346.

 

[Helio]

I'm unclear on what to make of the report. The stars, apparently, are very low in metals, so they formed in rather pristine conditions, as we expect from around 10 billion years ago, apparently.

But the surrounding clouds and filaments seem to have a higher level of metals. So, am I getting this wrong, or is there a disconnect between pristine stars and clouds?

I suppose new dust could have been injected by other encounters with dwarf galaxies, or perhaps the MW. Is this a consideration?

It's great the JWST is improving what could not be seen before!