The mass the run actually builds
The peer-reviewed AREPO radiation-hydrodynamic run by Chon, Springel and colleagues parks the Ishiyama-Hirano halo under far-ultraviolet flux from a luminous neighbour about 10 kpc away. Collapse starts at z of about 14; central protostars reach 5–9 × 10^5 solar masses, then supermassive-star collapse leaves seeds of about 10^6 solar masses. On the authors' own comparison, that sits an order of magnitude above canonical direct-collapse expectations.[1]
The same run grows a dense, optically thick disk around the seed and attributes broad Hα to electron scattering at a level the authors compare with JWST little red dots. Super-Eddington accretion then carries the mass to about 3 × 10^7 solar masses by z of about 8. The page records this mesh and this halo family.[1]
A spectral likeness is not a discovery
Unifying the little red dot with a short-lived, enshrouded heavy-seed phase is the run's proposed reading. Electron scattering is derived from the disk's optical depth; that geometry has not been independently measured in JWST. An alternative is that the V-shaped spectrum comes from another dense-shell or star-cluster geometry, and that this halo's special far-ultraviolet neighbour is rare in the universe.[1]
LISA strains of h_c about 10^−17–10^−16 at millihertz frequencies, and tens to hundreds of mergers in a 3-year mission, are extrapolations onto cosmological scales. The run shows which seed mass and shroud phase a later code must miss or match under a named calibration.[1]
The bound a second mesh can redraw
If a second radiation-hydrodynamic code, in an FUV neighbourhood of the same order, still leaves seeds above 10^6 solar masses, the heavy-seed channel tightens. If the seeds stay in the 10^5-solar-mass band, this AREPO family's deep potential well remains a chosen halo. The JWST objects themselves are not remeasured in this package.[1]