The "Panic!" part is the stark disparity between LambdaCDM predictions for galaxy formation and what is actually seen. JWST isn't the first to see this. Several other pre-JWST searches have seen the same thing. But the JWST data makes the evidence that this problem is real much more definitive.
direct me to where I can read about this?
If you want to do research on the issue, one of the common names for what the JWST is observing with great frequency is the "Impossible Early Galaxies Problem" discussed for example, in a
2015 preprint that was subsequently
published in 2016 in The Astrophysical Journal. The abstract of this paper states:
The current hierarchical merging paradigm and ΛCDM predict that the z∼4−8 universe should be a time in which the most massive galaxies are transitioning from their initial halo assembly to the later baryonic evolution seen in star-forming galaxies and quasars. However, no evidence of this transition has been found in many high redshift galaxy surveys including CFHTLS, CANDELS and SPLASH, the first studies to probe the high-mass end at these redshifts. Indeed, if halo mass to stellar mass ratios estimated at lower-redshift continue to z∼6−8, CANDELS and SPLASH report several orders of magnitude more M∼1012−13M⊙ halos than are possible to have formed by those redshifts, implying these massive galaxies formed impossibly early. We consider various systematics in the stellar synthesis models used to estimate physical parameters and possible galaxy formation scenarios in an effort to reconcile observation with theory. Although known uncertainties can greatly reduce the disparity between recent observations and cold dark matter merger simulations, even taking the most conservative view of the observations, there remains considerable tension with current theory.
Another paper discussing the subject in 2018 is:
To understand the formation and evolution of galaxies at redshifts z < 10, one must invariably introduce specific models (e.g., for the star formation) in order to fully interpret the data. Unfortunately, this tends to render the analysis compliant to the theory and its assumptions, so consensus is still somewhat elusive.
Nonetheless, the surprisingly early appearance of massive galaxies challenges the standard model, and the halo mass function estimated from galaxy surveys at z > 4 appears to be inconsistent with the predictions of LCDM, giving rise to what has been termed "The Impossibly Early Galaxy Problem" by some workers in the field. A simple resolution to this question may not be forthcoming.
The situation with the halos themselves, however, is more straightforward and, in this paper, we use linear perturbation theory to derive the halo mass function over the redshift range z < 10 for the R_h=ct universe. We use this predicted halo distribution to demonstrate that both its dependence on mass and its very weak dependence on redshift are compatible with the data.
The difficulties with LCDM may eventually be overcome with refinements to the underlying theory of star formation and galaxy evolution within the halos. For now, however, we demonstrate that the unexpected early formation of structure may also simply be due to an incorrect choice of the cosmology, rather than to yet unknown astrophysical issues associated with the condensation of mass fluctuations and subsequent galaxy formation.
Manoj K. Yennapureddy, Fulvio Melia, "
A Cosmological Solution to the Impossibly Early Galaxy Problem" (March 19, 2018).
Universe Today had an article on October 30, 2020 discussing the issue from an educated layman's perspective in reference primarily to the paper
The ALPINE-ALMA [CII] survey: Survey strategy, observations and sample properties of 118 star-forming galaxies at 4<z<6. The "money chart" in the Universe Today article is this one (which demonstrates what theory expected and what the ALPINE-ALMA survey compared to the theoretical expectation):
The Impossible Early Galaxy problem with the LambdaCDM standard model of cosmology is intimately intertwined with the
galaxy morphology problem, in which is explained this way at the link:
If galaxies grew hierarchically, then massive galaxies required many mergers.
Major mergers inevitably create a classical
bulge. On the contrary, about 80% of observed galaxies give evidence of no such bulges, and giant pure-disc galaxies are commonplace. The tension can be quantified by comparing the observed distribution of galaxy shapes today with predictions from high-resolution hydrodynamical cosmological simulations in the ΛCDM framework, revealing a highly significant problem that is unlikely to be solved by improving the resolution of the simulations. The high bulgeless fraction was nearly constant for 8 billion years.
This discussion cites in its support, the following three papers:
Kormendy, J.; Drory, N.; Bender, R.; Cornell, M.E. (2010). "Bulgeless giant galaxies challenge our picture of galaxy formation by hierarchical clustering".
The Astrophysical Journal.
723 (1): 54–80.
arXiv:
1009.3015.
Bibcode:
2010ApJ...723...54K.
doi:
10.1088/0004-637X/723/1/54.
S2CID 119303368.
Haslbauer, M; Banik, I; Kroupa, P; Wittenburg, N; Javanmardi, B (2022-02-01).
"The High Fraction of Thin Disk Galaxies Continues to Challenge ΛCDM Cosmology".
The Astrophysical Journal.
925 (2): 183.
arXiv:
2202.01221.
Bibcode:
2022ApJ...925..183H.
doi:
10.3847/1538-4357/ac46ac.
ISSN 1538-4357.
Sachdeva, S.; Saha, K. (2016). "Survival of pure disk galaxies over the last 8 billion years".
The Astrophysical Journal Letters.
820 (1): L4.
arXiv:
1602.08942.
Bibcode:
2016ApJ...820L...4S.
doi:
10.3847/2041-8205/820/1/L4.
S2CID 14644377.
