W.D.Clinger
Philosopher
- Joined
- Oct 3, 2009
- Messages
- 6,103
The following was posted in another thread, but it's more relevant to this thread and to Puppycow's link:
The ellipses and gray text are my edits. The bold face is as in the original abstract.
Carnall et al. said:Abstract
We report the spectroscopic confirmation of a massive quiescent galaxy, GS-9209 at a new redshift record of z = 4.658, just 1.25 Gyr after the Big Bang, using new deep continuum observations from JWST NIRSpec. From our full-spectral-fitting analysis, we find that this galaxy formed its stellar population over a ≃ 200 Myr period, approximately 600 − 800 Myr after the Big Bang (zform = 7.3 ± 0.2), before quenching at zquench = 6.7 ± 0.3. GS-9209 demonstrates unambiguously that massive galaxy formation was already well underway within the first billion years of cosmic history, with this object having reached a stellar mass of [greater than 10 billion suns] by z = 7. This galaxy also clearly demonstrates that the earliest onset of galaxy quenching was no later than ≃ 800 Myr after the Big Bang....it hosts an active galactic nucleus (AGN), for which we measure a black-hole mass of [400 to 630 million suns]....This intriguing object offers perhaps our deepest insight yet into massive galaxy formation and quenching during the first billion years of cosmic history.