Dust emission from the first massive galaxies

DE ROSSI, MARÍA EMILIA; RIEKE, GEORGE H.; SHIVAEI, IRENE; BROMM, VOLKER; LYU, JIANWEI

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

We compare observed far-infrared (FIR) galaxy spectral energy distributions (SEDs) at z ∼ 6 and theoretical predictions for first massive population II (Pop II) galaxies. Observed FIR SEDs at z > 5 are broad and shifted to bluer wavelengths when compared to galaxies at z ∼ 3. By implementing an analytical model for dust emission from Pop II massive galaxies, we were able to reproduce the observed behaviour as a consequence of the high energy densities and silicate-rich dust composition of high-z model galaxies. As noted in a previous work, the non-blackbody nature of galaxy SEDs at z ∼ 6 should be taken into account when interpreting measurements of FIR luminosities to avoid underestimating star formation rates.