The Physical Drivers of the Luminosity-weighted Dust Temperatures in High-redshift Galaxies

The underlying distribution of galaxies' dust SEDs (i.e., their spectra re-radiated by from rest-frame $\sim$3$\mu$m-3mm) remains relatively unconstrained due to a dearth FIR/(sub)mm data for large samples galaxies. It has been claimed in the literature that galaxy's temperature -- observed as wavelength where SED peaks ($\lambda_{peak}$) is traced most closely its specific star-formation rate (sSFR) or parameterized 'distance' SFR-M$_\star$ relation (the galaxy 'main sequence'). We present 0.24" resolved 870$\mu$m ALMA continuum observations seven $z=1.4-4.6$ dusty star-forming galaxies (DSFGs) chosen have range well-constrained luminosity-weighted temperatures. also draw on similar resolution maps sample ALESS submillimeter Hodge et al. (2016). constrain physical scales over which radiates and compare those measurements characteristics integrated SED. confirm significant correlations $\lambda_{peak}$ with both L$_{IR}$ (or SFR) $\Sigma_{\rm IR}$ ($\propto$SFR surface density). investigate correlation between $\log_{10}$($\lambda_{peak}$) $\log_{10}$($\Sigma_{\rm IR}$) find hold would be expected Stefan-Boltzmann Law, effective size an equivalent blackbody. sSFR distance are less than L$_{IR}$; therefore, we conclude more fundamental tracer temperatures indeed densities line local Universe results, relate geometry ISM.