Galaxy candidates, 16 < z < 18

[mikehelland]

https://arxiv.org/abs/2411.13640

[LifeIsStrange]

Was about to post it!

clear tension with pre-JWST theoretical predictions, extending the over-abundance of galaxies from z∼10 to z∼18.6.

Would be nice to update the prediciton of star formation models and MOND.
Are those only photometric or is the some spectroscopy ? (they seem to mention balmer breaks), as there already were Z=20 photometric candidates.
Moreover I'd like to state that the redshift barrier has already been well broken, the resultsts are 2 years old but gatekeeped/not published yet... as can be seen from the various scheduled high Z observations in JWST cycle 2 and cycle 3

[RedshiftDrift]

All are photometric estimates.
Yan et al. http://arxiv.org/abs/2311.15121 have candidates up to $z=21.8$.

Using this cosmo calculator
https://cosmology.info/code/marmet_l/cosmology-calculators.html (a copy of Wright's, but with a second calculator for a static cosmology)
At z = 21.8 the LCDM universe is only 159 Myr-old. That's not enough time to build a galaxy.
At z = 21.8 the galaxy is 41.3 Gly away in a static universe.

Still waiting for a spectroscopic confirmation with enough resolution to see the Lyman line...

[LifeIsStrange]

As you can see figure 6 the z=18.6 galaxy is still permitted by LCDM if and only if there is 100% baryon conversion efficiency to stars and exponential star formation history.
What is not reported however is that this is only true for H0=70.
Using this cosmo calculator
https://www.astro.ucla.edu/~wright/CosmoCalc.html
With the value of the hubble tension as backed by JWST and countless probes except cmb/bao data, with H0=73km the age of the galaxy change from
195Myr to 187Myr.
This small difference is it seems sufficient to 100% rule out LCDM empirically, even with the wildest star formation mechanisms since the limiting factor here is dark matter halo formation time.

This should be known as the new Hubble tension where the standard model is ruled out under the most proven value ("infinite" sigmas), which is historic.

Btw > The upper limits reach ∼ 10−6 Mpc−3 mag−1 (for CEERS plus PRIMER) at MUV ∼ −19, in a stark contrast to GLIMPSE where we predict there are ≳ 2000× more galaxies per volume at MUV = −18.