Relaño, M.Lisenfeld, U.Pérez González, Pablo GuillermoVílchez, J. M.Battaner, E., E.2023-06-202023-06-202007-10-010004-637X10.1086/522371https://hdl.handle.net/20.500.14352/51937© 2007 The American Astronomical Society. All rights reserved. We would like to thank the anonymous referee and Almudena Zurita for useful suggestions that improved the final version of the manuscript. This work has been supported by the Spanish Ministry of Education and Science within the PNAYA via projects AYA2004-08251-C02-00, and ESP2003-00915. P. G. P.- G. acknowledges support from the Ramón y Cajal Fellowship Program and the project AYA 2006-02358.We investigate the use of the rest-frame 24 μm luminosity as an indicator of the star formation rate (SFR) in galaxies with different metallicities by comparing it to the (extinction-corrected) Hα luminosity. We carry out this analysis in two steps: First, we compare the emission from H (II) regions in different galaxies with metallicities between 12 + and 8.9. We find that the 24 μm and the extinction-corrected Hα luminosities from individual H (II) log (O/H) = 8.1 regions follow the same correlation for all galaxies, independent of their metallicity. Second, the role of metallicity is explored further for the integrated luminosity in a sample of galaxies with metallicities in the range of 12 +. For this sample we compare the 24 μm and Hα luminosities integrated over the entire galaxies log (O/ H) = 7.2-9.1 and find a lack of the 24 μm emission for a given Hα luminosity for low-metallicity objects, likely reflecting a low dust content. These results suggest that the 24 μm luminosity is a good metallicity-independent tracer for the SFR in individual H (II) regions. On the other hand, metallicity has to be taken into account when using the 24 μm luminosity as a tracer for the SFR of entire galaxies.engjournal articlehttp://dx.doi.org/10.1086/522371http://iopscience.iop.org/open access52H-II-regionsElemental abundance variationsMultiband imaging photometerPrimordial helium abundanceStarburst galaxy NGC-1705Spitzer-space-telescopeBlue compact galaxiesGroup dwarf galaxiesInfrared galaxiesIonized-gasAstrofísicaAstronomía (Física)