Poster Presentation

Exploring the Nature of First Galaxies with JWST and ALMA

Author(s): María Emilia, De Rossi (Institute for Astronomy and Space Physics, Argentina) & Volker, Bromm (University of Texas at Austin, USA)

Presenter: María Emilia De rossi (Institute for Astronomy and Space Physics)

By applying a model of primeval dust, we predict the FIR-continuum luminosities of massive galaxies such as those detected by the JWST at z>7. According to our results, upper FIR flux limits inferred from ALMA observations can constrain dust fractions and ISM metallicities in primeval galaxy sources. Encouragingly, when adopting model parameters (e.g. star formation efficiency, gas metallicity, dust-to-metal mass ratio) expected for typical first galaxies, our predicted FIR spectra are in agreement with upper flux limits derived from ALMA. In particular, higher values for the gas metallicity (> 5x10**-2 Zsun) and dust-to-metal ratio (> 0.06) are ruled out by current observations, unless a higher star formation efficiency is assumed. Our results suggest that ALMA multi-band observations could help to address the chemical composition of dust and its grain size distribution in the early universe.
In the future, a crucial challenge would involve not only an improvement of the FIR sensitivities, but also extending the wavelength coverage along different ALMA bands.