SIMBAD references

Polycyclic aromatic hydrocarbon (PAH) emission has long been proposed to be a potential star formation rate indicator, as it arises from the photodissociation region bordering the Stromgren sphere of young, massive stars. We apply a recently developed technique of mid-infrared spectral decomposition to obtain a uniform set of PAH measurements from Spitzer low-resolution spectra of a large sample of star-forming galaxies spanning a wide range in stellar mass (M_* ≃ 10⁶-10^11.4 M_☉) and star formation rate (∼0.1-2000 M_☉ yr^–1). High-resolution spectra are also analyzed to measure [Ne II] 12.8 µm and [Ne III] 15.6 µm, which effectively trace the Lyman continuum. We present a new relation between PAH luminosity and star formation rate based on the [Ne II] and [Ne III] lines. Calibrations are given for the integrated 5-15 µm PAH emission, the individual features at 6.2, 7.7, 8.6, and 11.3 µm, as well as several mid-infrared bandpasses sensitive to PAH. We confirm that PAH emission is suppressed in low-mass dwarf galaxies, and we discuss the possible physical origin of this effect.