Revision 2

Accepted · core change · record

Changes against revision 1:

Title: Do any early JWST galaxies exceed the LCDM baryon budget?
Plain: A galaxy cannot contain more stars than the total ordinary matter available in its dark matter halo. If some early galaxies break this rule, the standard cosmological model itself would be in trouble.
Precise · changed · core: Revision 1: For a survey volume $V$ at redshift $z$, the most massive LCDM halo M_h,max(z, V) bounds the stellar mass by M_* <= f_b M_h,max with $f_b = \Omega_b / \Omega_m \sim 0.16$. Determine whether any galaxy with spectroscopic redshift and stellar mass corrected for active-galactic-nucleus light violates this bound.; Revision 2: For a survey volume $V$ at redshift $z$, the most massive LCDM halo $M_h,\mathrm{max}(z, V)$ bounds the stellar mass by $M_* \le f_b M_h,\mathrm{max}$ with $f_b = \Omega_b / \Omega_m \sim 0.16$. Determine whether any galaxy with spectroscopic redshift and stellar mass corrected for active-galactic-nucleus light violates this bound.
Settled by: Spectroscopic redshifts and dynamical or multi-band stellar masses for the most massive candidates at $z > 7$.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: partially-resolved
Status note: Several early photometric massive candidates were revised downward after spectroscopy or reclassified as active nuclei; no confirmed violation is established.
Posed since: 2023

Decisions