Dissecting Nearby Galaxies with piXedfit. II. Spatially Resolved Scaling Relations among Stars, Dust, and Gas

August 2022 • 2022ApJ...935...98A

Authors • Abdurro'uf • Lin, Yen-Ting • Hirashita, Hiroyuki • Morishita, Takahiro • Tacchella, Sandro • Wu, Po-Feng • Akiyama, Masayuki • Takeuchi, Tsutomu T.

Abstract • We study spatially resolved scaling relations among stars, dust, and gas in ten nearby spiral galaxies. In a preceding paper, we have derived spatially resolved properties of the stellar population and dust by a panchromatic spectral energy distribution fitting using piXedfit. Now, we investigate resolved star formation ( ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ -ΣSFR*) and dust scaling relations. While the relations with all subgalactic regions of the galaxies are reasonably tight (σ ≲ 0.3 dex), we find that most of the scaling relations exhibit galaxy-to-galaxy variations in normalization and shape. Only two relations of Σdustgas and Σdust- ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ do not show noticeable galaxy-to-galaxy variations among our sample galaxies. We further investigate the correlations among the scaling relations. We find significant correlations among the normalization of the ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ -ΣSFR* relations, which suggest that the galaxies with higher levels of resolved H2 fraction ( ${f}_{{{\rm{H}}}_{2}}$ ) tend to have higher levels of resolved star formation efficiency (SFE) and specific star formation rate (sSFR). We also observe that the galaxies with higher levels of resolved dust-to-stellar mass ratios tend to have higher levels of resolved sSFR, SFE, and ${f}_{{{\rm{H}}}_{2}}$ . Moreover, we find that the galaxies with higher global sSFR and less compact morphology tend to have higher levels of the resolved sSFR, SFE, and ${f}_{{{\rm{H}}}_{2}}$ , which can explain the variations in the normalization of the ${{\rm{\Sigma }}}_{{{\rm{H}}}_{2}}$ -ΣSFR* relationships. Overall, we observe indications of the contributions of both global and local factors in governing the star formation process in galaxies.


IPAC Authors


Takahiro Morishita

Assistant Scientist