At z=1−3, the formation of new stars is dominated by dusty galaxies whose
far-IR emission indicates they contain colder dust than local galaxies of a
similar luminosity. We explore the reasons for the evolving IR emission of
similar galaxies over cosmic time using: 1) Local galaxies from GOALS (LIR=1011−1012L⊙); 2) Galaxies at z∼0.1−0.5 from the 5MUSES
(LIR=1010−1012L⊙); 3) IR luminous galaxies spanning
z=0.5−3 from GOODS and Spitzer xFLS (LIR>1011L⊙). All
samples have Spitzer mid-IR spectra, and Herschel and ground-based
submillimeter imaging covering the full IR spectral energy distribution,
allowing us to robustly measure LIRSF,
Tdust, and Mdust for every galaxy. Despite similar infrared
luminosities, z>0.5 dusty star forming galaxies have a factor of 5 higher
dust masses and 5K colder temperatures. The increase in dust mass is linked
with an increase in the gas fractions with redshift, and we do not observe a
similar increase in stellar mass or star formation efficiency.
L160SF/L70SF, a proxy
for Tdust, is strongly correlated with LIRSF/Mdust independently of redshift. We
measure merger classification and galaxy size for a subsample, and there is no
obvious correlation between these parameters and LIRSF/Mdust or L160SF/L70SF. In dusty star forming galaxies, the
change in LIRSF/Mdust can fully
account for the observed colder dust temperatures, suggesting that any change
in the spatial extent of the interstellar medium is a second order effect.Comment: Accepted for publication in ApJ. 21 pages, 11 figure