Signatures of first galaxies at FIR/sub-mm wavelengths

DE ROSSI, MARÍA EMILIA; BROMM, VOLKER

Congreso; 61a Reunión de la Asociación Argentina de Astronomía; 2019

We explore the possibility of detecting first galaxies with a generic far-infrared/sub-millimeter telescope by applying an analytical model of primordial dust emission. As shown in previous works, galaxies at redshifts z > 7 experience a strong negative K-correction in such a way that systems of similar masses are brighter at higher z. In addition, at a given mass and z, our model predicts that luminosity fluxes increase proportionally to the dust-to-metal ratios (D/M) of primeval sources. We evaluate the observability of model sources at different z > 7 as a function of the observed survey area (∆Ω) and sensitivity (S) of a generic instrument. Assuming ∆Ω ∼ 10 deg 2 and a plausible S ∼ 1 µJy for a near future survey, we could assure the detection of at least one typical source with D/M ∼ 5 × 10 −3 at z > 7. For S > 1 µJy and ∆Ω < 10 deg^2, higher than typical D/M are required to detect at least one individual source at z > 7. The observability of model galaxies is also affected by the size distribution of dust grains, specially towards higher z.