Abstract
Integrating our knowledge of star formation traced by observations at
different wavelengths is essential for correctly interpreting and comparing
star formation activity in a variety of systems and environments. This study
compares extinction corrected integrated ultraviolet (UV) emission from
resolved galaxies with color-magnitude diagram (CMD) based star formation rates
(SFRs) derived from resolved stellar populations and CMD fitting techniques in
19 nearby starburst and post-starburst dwarf galaxies. The datasets are from
the panchromatic STARBurst IRregular Dwarf Survey (STARBIRDS) and include deep
legacy GALEX UV imaging, HST optical imaging, and Spitzer MIPS imaging. For the
majority of the sample, the integrated near UV fluxes predicted from the
CMD-based SFRs - using four different models - agree with the measured,
extinction corrected, integrated near UV fluxes from GALEX images, but the far
UV predicted fluxes do not. Further, we find a systematic deviation between the
SFRs based on integrated far UV luminosities and existing scaling relations,
and the SFRs based on the resolved stellar populations. This offset is *not*
driven by different star formation timescales, variations in SFRs, UV
attenuation, nor stochastic effects. This first comparison between CMD-based
SFRs and an integrated FUV emission SFR indicator suggests that the most likely
cause of the discrepancy is the theoretical FUV-SFR calibration from stellar
evolutionary libraries and/or stellar atmospheric models. We present an
empirical calibration of the FUV-based SFR relation for dwarf galaxies, with
uncertainties, which is ~65% larger than previous relations.
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