VALES: III. The calibration between the dust continuum and interstellar gas content of star-forming galaxies

Abstract

We present the calibration between the dust continuum luminosity and interstellar gas content obtained from the Valparaíso ALMA Line Emission Survey (VALES) sample of 67 main-sequence star-forming galaxies at 0.02<$z$<0.35. We use CO(1-0) observations from the Atacama Large Millimetre/submillimetre Array (ALMA) to trace the molecular gas mass, $M_{{\mathrm{H}}_2}$, and estimate the rest-frame monochromatic luminosity at 850 $\hat{I}¼$m, $L_{\hat{I}{½}_{850}}$, by extrapolating the dust continuum from MAGPHYS modelling of the far-ultraviolet to submillimetre spectral energy distribution sampled by the Galaxy And Mass Assembly (GAMA) survey. Adopting $\hat{I}{\pm }_{\mathrm{CO}}$ = 6.5 (K km s${}^{-1}$ pc${}^2$)${}^{-1}$, the average ratio of $L_{\hat{I}{½}_{850}}/M_{{\mathrm{H}}_2}$ = (6.4$\pm$1.4)$\times 10^{19}$ erg s${}^{-1}$ Hz${}^{-1}$ ${\mathrm{M}}_{\odot }^{-1}$, in excellent agreement with literature values. We obtain a linear fit of ${\log }_{10}$ ($M_{{\mathrm{H}}_2}/{\mathrm{M}}_{\odot }$) = (0.92$\pm$0.02) ${\log }_{10}$ ($L_{\hat{I}{½}_{850}}$/erg s${}^{-1}$ Hz${}^{-1}$)-(17.31$\pm$0.59). We provide relations between $L_{\hat{I}{½}_{850}}$, $M_{{\mathrm{H}}_2}$ and $M_{\mathrm{ISM}}$ when combining the VALES and literature samples, and adopting a Galactic $\hat{I}{\pm }_{\mathrm{CO}}$ value.

Accepted for publication in MNRAS. 5 pages, including 2 figures and 1 table