SDSS+JWST Census of Stellar and Nebular Dust Attenuation at $z\sim 0$-7: Mass Dependence and Redshift Evolution

We present the demography of dust attenuation, including its mass dependence and redshift evolution, using spectroscopic samples of 34,182 SDSS galaxies at $z\sim 0.1$ and 863 JWST/JADES galaxies at $z\sim 1.5$–$7$. We find that, on average, $\mathrm{H}\alpha \mathrm{/}\mathrm{H}\beta$ ratios are comparable to the Case B recombination value at $M_{\ast }\lesssim {10}^9{M}_{\odot }$, and increase beyond $M_{\ast }\sim {10}^9{M}_{\odot }$ both at $z\sim 0.1$ and $1.5$–$7$. We derive the nebular attenuation $A_{\mathrm{V},\mathrm{n}\mathrm{e}\mathrm{b}\mathrm{u}\mathrm{l}\mathrm{a}\mathrm{r}}$ from Balmer decrements and the stellar attenuation $A_{\mathrm{V},\mathrm{s}\mathrm{t}\mathrm{e}\mathrm{l}\mathrm{l}\mathrm{a}\mathrm{r}}$ from rest-frame UV–optical spectra with supplementary $\mathit{\text{GALEX}}$ data, via comparisons with stellar-population models and multiple attenuation curves in a consistent manner across cosmic time. We find no significant redshift evolution of $A_{\mathrm{V},\mathrm{n}\mathrm{e}\mathrm{b}\mathrm{u}\mathrm{l}\mathrm{a}\mathrm{r}}$ and $A_{\mathrm{V},\mathrm{s}\mathrm{t}\mathrm{e}\mathrm{l}\mathrm{l}\mathrm{a}\mathrm{r}}$ at fixed $M_{\ast }$ over $z\sim 0$–$7$, forming a universal extinction relation, and both rise from $0.2$–$0.4$ at $M_{\ast }\lesssim {10}^9{M}_{\odot }$ to $\sim 1$ at $M_{\ast }\sim {10}^{11}{M}_{\odot }$. Interestingly, at $M_{\ast }\gtrsim {10}^9{M}_{\odot }$, $A_{\mathrm{V},\mathrm{n}\mathrm{e}\mathrm{b}\mathrm{u}\mathrm{l}\mathrm{a}\mathrm{r}}$ rises more steeply than $A_{\mathrm{V},\mathrm{s}\mathrm{t}\mathrm{e}\mathrm{l}\mathrm{l}\mathrm{a}\mathrm{r}}$. This correlation holds within an uncertainty of $\sim \pm 0.2$ for various combinations of attenuation curves (Calzetti, SMC, and Milky Way). These results indicate that $M_{\ast }\sim {10}^9{M}_{\odot }$ is a transition mass in dust attenuation, whose low-mass behavior reflects dust widely distributed by feedbacks. These mass-dependent extinction results address the long-standing issue of appropriate choice of the stellar-to-nebular color excess ratio, $f\equiv E(B-V{)}_{\mathrm{s}\mathrm{t}\mathrm{e}\mathrm{l}\mathrm{l}\mathrm{a}\mathrm{r}}\mathrm{/}E(B-V{)}_{\mathrm{n}\mathrm{e}\mathrm{b}\mathrm{u}\mathrm{l}\mathrm{a}\mathrm{r}}=1.0$ or $0.44$, and suggest that galaxy $M_{\ast }$ determines $f$ from $\sim 1.0$ to $\sim 0.44$ across low- to high-mass galaxies.