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Arxiv: CEERS: 7.7 μm PAH Star Formation Rate Calibration with JWST MIRI Published: 10/11/2023 9:00:02 PM Updated: 10/11/2023 9:00:02 PM

Paper abstract: We test the relationship between UV-derived star formation rates (SFRs) andthe 7.7 {\mu}m polycyclic aromatic hydrocarbon (PAH) luminosities from theintegrated emission of galaxies at z ~ 0 - 2. We utilize multi-band photometrycovering 0.2 - 160 {\mu}m from HST, CFHT, JWST, Spitzer, and Herschel forgalaxies in the Cosmic Evolution Early Release Science (CEERS) Survey. Weperform spectral energy distribution (SED) modeling of these data to measuredust-corrected far-UV (FUV) luminosities, L_{FUV}, and UV-derived SFRs. Wethen fit SED models to the JWST/MIRI 7.7 - 21 {\mu}m CEERS data to deriverest-frame 7.7 {\mu}m luminosities, L_{770}, using the average flux densityin the rest-frame MIRI F770W bandpass. We observe a correlation betweenL_{770} and L_{FUV}, where log L_{770} is proportional to (1.27+/-0.04)log L_{FUV}. L_{770} diverges from this relation for galaxies at lowermetallicities, lower dust obscuration, and for galaxies dominated by evolvedstellar populations. We derive a "single-wavelength" SFR calibration forL_{770} which has a scatter from model estimated SFRs({{\sigma}_{{\Delta}SFR}}) of 0.24 dex. We derive a "multi-wavelength"calibration for the linear combination of the observed FUV luminosity(uncorrected for dust) and the rest-frame 7.7 {\mu}m luminosity, which has ascatter of {{\sigma}_{{\Delta}SFR}} = 0.21 dex. The relatively small decreasein {\sigma} suggests this is near the systematic accuracy of the total SFRsusing either calibration. These results demonstrate that the rest-frame 7.7{\mu}m emission constrained by JWST/MIRI is a tracer of the SFR for distantgalaxies to this accuracy, provided the galaxies are dominated bystar-formation with moderate-to-high levels of attenuation and metallicity.