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Pah and Mid-IR Luminosities as Measures of Star-Formation Rate in Spitzer First Look Survey Galaxies

H. Wu·C. Cao·C. -N. Hao·F. -S. Liu·J. -L. Wang·X. -Y. Xia·Z. -G. Deng·C. -K. -S. Young
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Abstract

We present evidence that the 8 $μ$m (dust) and 24 $μ$m luminosities of star-forming galaxies are both strongly correlated with their 1.4 GHz and H$α$ luminosities over a range in luminosity of two-to-three orders of magnitude. At the bright end, the correlations are found to be essentially linear over a luminosity range of about two orders of magnitude (corresponding to star-formation rates of several-tenths to several tens of solar masses per year). However, at the faint end, there appears to be a slope change for dwarf galaxies, possibly due to the lower dust-to-gas ratios and lower metallicities of the dwarfs. The correlations suggest that PAH features and mid-IR continuum emissions are good measures of the star formation rates of galaxies, and we present calibrations of star-formation rates based on existing radio and H$α$ relations. Our findings are based on a sample of star-forming galaxies selected from the main field of the Spitzer First Look Survey with the aid of spectroscopic data from the Sloan Digital Sky Survey and VLA 1.4 GHz data.

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H. Wu, C. Cao, C. -N. Hao, F. -S. Liu, J. -L. Wang, X. -Y. Xia, Z. -G. Deng, C. -K. -S. Young. 2005-10-14. Pah and Mid-IR Luminosities as Measures of Star-Formation Rate in Spitzer First Look Survey Galaxies. https://doi.org/10.1086/497961

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