The Impact of Inclination-dependent Attenuation on Ultraviolet Star Formation Rate Tracers [GA]

http://arxiv.org/abs/2204.09580


We examine and quantify how hybrid (e.g., UV+IR) star formation rate (SFR) estimators and the $A_{\rm FUV}$-$\beta$ relation (i.e., the Meurer et al. 1999 relation) depend on inclination for disk-dominated galaxies using spectral energy distribution modeling that utilizes the inclination-dependent attenuation curves described in Doore et al. (2021). We perform this analysis on a sample of 133 disk-dominated galaxies from the CANDELS fields and 18 disk galaxies from the SINGS and KINGFISH samples. We find that both the hybrid SFR estimators and the $A_{\rm FUV}$-$\beta$ relation present clear dependencies on inclination. To quantify this dependence in hybrid SFR estimators, we derive an inclination and FUV-NIR color dependent parametric relation for converting observed UV and IR luminosities into SFRs. For the $A_{\rm FUV}$-$\beta$ relation, we introduce an inclination-dependent component that accounts for the majority of the inclination dependence with the scatter of the relation increasing with inclination. We then compare both of these inclination-dependent relations to similar inclination-independent relations found in the literature. From this comparison, we find that the UV+IR correction factor and $A_{\rm FUV}$ for our our hybrid and $A_{\rm FUV}$-$\beta$ relations, respectively, result in a reduction in the residual scatter of our sample by approximately a factor of two. Therefore, we demonstrate that inclination must be considered in hybrid SFR estimators and the $A_{\rm FUV}$-$\beta$ relation to produce more accurate SFR estimates in disk-dominated galaxies.

Read this paper on arXiv…

K. Doore, R. Eufrasio, B. Lehmer, et. al.
Thu, 21 Apr 22
45/73

Comments: 24 pages, 15 figures. 23 page body and 1 page appendix. Accepted to ApJ