The dust mass in z > 6 normal star-forming galaxies

摘要: We interpret recent ALMA observations of z > 6 normal star forming galaxies by means a semi-numerical method, which couples the output cosmological hydrodynamical simulation with chemical evolution model accounts for contribution to dust enrichment from supernovae, asymptotic giant branch stars and grain growth in interstellar medium. find that while stellar sources dominate mass small galaxies, higher level metal experienced Mstar 10 9 M⊙ allows efficient growth, provides dominant mass. Even assuming maximally efficientsupernova production, observed = 7.5 galaxy A1689-zD1 requires very growth. This, turn, implies this average density cold dense gas, where occurs, is comparable inferred QSO host at similar redshifts. Although plausible, upper limits on continuum emission 6.5 < show these conditions must not apply bulk high redshift population.