Abstract
We present the spatially resolved relationship between the dust-to-gas mass ratio (DGR) and gas-phase metallicity ($Z_{\rm gas}$ or 12 + log(O/H)) (i.e. DGR-$Z_{\rm gas}$ relation) of 11 nearby galaxies with a large-metallicity range (1.5 dex of 12 + log(O/H)) at (sub-)kpc scales. We used the large field-of-view ($\gtrsim$ 3 arcmin) optical pseudo-Integral Field Spectroscopy data taken by the TYPHOON/Progressive Integral Step Method survey, covering the optical size of galaxies, combining them with multiwavelength data [far-ultrviolet (UV) to far-infrared (IR), CO, and H I 21 cm radio]. A large scatter of DGR in the intermediate-metallicity galaxies (8.0 $\lt $ 12 + log(O/H)$\lt $ 8.3) is found, which is in line with dust evolution models, where grain growth begins to dominate the mechanism of dust mass accumulation. In the lowest metallicity galaxy of our sample, Sextans A (12 + log(O/H)$\lt $ 7.6), the star-forming regions have significantly higher DGR values (by 0.5-2 dex) than the global estimates from literature at the same metallicity, but aligns with the DGR values from metal depletion method from damped Lyman alpha systems and high hydrogen gas density regions of Sextans A. Using dust evolution models with a Bayesian Monte Carlo Markov Chain approach suggests: (1) a high supernova dust yield and (2) a negligible amount of photofragmentation by UV radiation, although we note that our sample in the low-metallicity regime is limited to Sextans A. On the other hand, it is also possible that while metallicity influences DGR, gas density also plays a role, indicating an early onset of dust grain growth in the dust mass build-up process despite its low metallicity.
