The Prevalence and Properties of Dusty Galaxies Through Cosmic Time

Nicholas Martis (Tufts)
Friday, April 26, 2019 - 2:15pm to 3:00pm

From a combination of UltraVISTA and 3D-HST data we measure the evolution of the fractions of quiescent galaxies, moderately unobscured star-forming galaxies, and dusty star-forming galaxies as a function of stellar mass since z = 3. Motivated by the finding that dusty star-forming galaxies become more prevalent both with increasing stellar mass and increasing redshift, we investigate the stellar and dust properties of a stellar mass complete sample of massive (logM∗/M ≥ 10.5) and dusty (Av ≥ 1) galaxies at 1 ≤ z ≤ 4 by modeling their UV-to-infrared spectral energy distributions (SEDs) obtained from the combination of UltraVISTA DR3 photometry and Herschel PACS-SPIRE data using MAGPHYS. We evaluate the ability of the rest-frame UVJ color-color diagram to determine the star formation and dust obscuration properties for our sample. We construct median SEDs of massive, dusty galaxies as a function of redshift and star-formation activity (quiescent vs star-forming). Simultaneous modeling of the panchromatic SED allows us to quantify the contribution to the IR emission from dust heated by star formation rather than evolved stellar populations, which we find to be a crucial element in characterizing these galaxies correctly. I summarize the stellar population and dust properties of the sample of massive and dusty galaxies at z > 1, including, but not limited to, the relation between dust mass and star-formation rate, the relations between specific star-formation rate and diagnostics of the conditions of the interstellar medium, and the relation between the IRX and the UV slope. The studied sample at z > 1 is finally compared to local galaxies.

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