Probing star formation and ISM properties using galaxy disk inclination

Abstract

We evaluate dust-corrected far-ultraviolet (FUV) star formation rates (SFRs) for samples of star-forming galaxies at z ~ 0 and z ~ 0.7 and find significant differences between values obtained through corrections based on UV colour, from a hybrid mid-infrared (MIR) plus FUV relation, and from a radiative transfer based attenuation correction method. The performances of the attenuation correction methods are assessed by their ability to remove the dependency of the corrected SFR on inclination, as well as returning, on average, the expected population mean SFR. We find that combining MIR (rest-frame ~ 13 μm) and FUV luminosities gives the most inclination-independent SFRs and reduces the intrinsic SFR scatter of the methods we tested. However, applying the radiative transfer based method also gives corrections to the FUV SFR that are inclination independent and in agreement with the expected SFRs at both z ~ 0 and z ~ 0.7. SFR corrections based on the UV-slope perform worse than the other two methods we tested. For our local sample, the UV-slope method works on average, but does not remove inclination biases. At z ~ 0.7, we find that the UV-slope correction we used locally flattens the inclination dependence compared to the raw FUV measurements, but was not sufficient to correct for the large attenuation observed at z ~ 0.7.