Applicability of the adopted IMF to a luminous z=14.44 galaxy

Determine whether the initial mass function adopted in the Prospector SED modeling (a Salpeter 1955 IMF with a 100 M⊙ upper-mass cutoff within BPASS v2.2 models) is applicable to the luminous z=14.44 galaxy MoM-z14, in order to assess the reliability of derived stellar masses, star-formation rates, and related quantities for such early-universe systems.

Background

The paper derives physical properties of MoM-z14 using Prospector with BPASS v2.2 stellar population models and a Salpeter IMF with a 100 M⊙ upper-mass cutoff. The authors caution that systematic uncertainties may affect these inferences because the stellar initial mass function at z≈14 could deviate from canonical prescriptions.

They note ongoing discussions in the literature about potentially top-heavy IMFs or very massive stars in the earliest galaxies, which would alter inferred stellar masses, star-formation rates, and ionizing photon production. Establishing whether the adopted IMF is valid for MoM-z14 is therefore critical for interpreting its derived physical properties and for comparisons to theoretical models of early galaxy formation.