2013MNRAS.433.1039Z

Calibrations of star formation rate (SFR) are affected by many factors, for example the metallicity, the initial mass function (IMF) and the evolutionary population synthesis (EPS) model used. In this paper we will discuss the effects of binary interactions, metallicity, EPS model and IMF on several widely used SFR calibrations based on the EPS models of Yunnan with and without binary interactions, BC03, sb99, pégase and POPSTAR. The inclusion of binary interactions makes these SFR conversion coefficients smaller (by less than 0.2 dex), and these differences increase with metallicity. The differences in the calibration coefficient between the SFR and the luminosity of the Hα recombination line (CHα) and that between the SFR and the ultraviolet (UV) fluxes at 1500 and 2800 Å (Ci, UV), caused by the IMF, are independent of metallicity (0.03-0.33 dex), except for ΔCHα, IMF when using the POPSTAR and for ΔCi, UV, IMF when using the pégase models. Moreover, we find that L2800 is not suitable for the linear calibration of SFR at low metallicities.

Finally, we compare the effects of these factors on the SFR calibrations considered in this paper. The effects of metallicity/IMF and EPS model on CHα and CFIR (the conversion coefficient between SFR and the far-infrared flux) are the largest among these factors, respectively. For the calibration between SFR and Ci, UV, the effects of these factors are comparable.