Mid- and Far-infrared Color–Color Relations within Local Galaxies

We present an extensive archival analysis of a sample local galaxies, combining multi-wavelength data from GALEX, Spitzer and Herschel to investigate "blue-side" mid-infrared (MIR) "red-side" far-infrared (FIR) color-color correlations within the observed infrared spectral energy distributions (IR SEDs). Our largely consists KINGFISH with important addition select few including NGC5236 (M83) NGC4449. With far-ultraviolet FUV (${\sim}0.15$ $\mu$m) through 500 $\mu$m convolved common angular resolution, we measure photometry $kpc$-scale star-forming regions 36$"\times$36$"$ in size. Star formation rates (SFRs), stellar masses metallicity are derived throughout our sample. Focusing on $f_{70}/f_{500}$ "FIR" $f_{8}/f_{24}$ "MIR" flux density ratios (colors), find that sub-sample galaxies demonstrate strong IR correlation their regions, while others uncorrelated colors. This division is driven by two main effects: 1) strength star (SF) 2) metal content interstellar medium (ISM). Galaxies uniformly dominated high surface densities SF (e.g. NGC5236) correlations, exhibit lower levels mixed environments NGC5457) weaker or no correlation--explained increasing effect varying ISM heating colors, specifically MIR. large dispersion SFR-$L_{8}$ (8 luminosity) relation traced distributions, consistent extant studies, highlighting its problematic use as SFR indicator across diverse systems/samples.