I do not get that these distant galaxies are magnified because of the expansion between then and now?
In what way are they magnified?
Read the article, one of the galaxies was measured as having about 100,000,000,000 times the mass of our star.
OK, let's read the original article, OK? Here it is:
https://arxiv.org/pdf/2211.05792.pdf
Here's the conclusion from that paper:
"We explore several potential explanations for these unexpected results. While not the most exciting, significant sample contamination cannot be conclusively ruled
out. These data represent our first foray into a new cosmic epoch, and spectroscopic confirmation of the red-
shifts to at least a subset of these ultra-high-redshift
sources are necessary to gain confidence in our sample
selection processes. However, such data will begin to
flow soon, with CEERS scheduled to spectroscopically
observe ∼10 of these sources in late 2022 (though these
high redshifts may necessitate longer exposure times for
future cycle programs).
Should these high abundances of z = 9–13 galaxies
be confirmed, we explore what possible changes in the
models could bring their predictions into agreement with
observations. One very exciting possibility is that we are
beginning to probe an era where star-formation in galax-
ies is dominated by a top-heavy IMF due to the pres-
ence of very low metallicities, which could increase the
ratio of UV luminosity per unit halo mass. "
Here are a few other papers based on JWST data:
Search | arXiv e-print repository
Have fun!