Constraints on CMBR Flux due to High- z Dust Emission

Abstract E. Gjergo & P. Kroupa have proposed a new foreground cosmic microwave background radiation (CMBR) component produced by dust associated with the progenitor clouds at z = 15–20 that led to the formation of massive early-type galaxies, calculating that a minimum of 1.4% and a maximum of 100% of the whole CMBR radiation would be produced by this mechanism. Here, I check how much dust emission is compatible with the spectrum of the CMBR monopole flux measurements within the corresponding errors. COBE-FIRAS monopole is fitted to different models with different dust emissivity spectral indexes ( β ) and dispersion of redshifts of the progenitor clouds ( σ d ). Within the realistic values of β ≥ 0.5, σ d ≥ 0.8, the contamination of CMBR flux by high z dust should be