Integrated and resolved dust attenuation in clumpy star-forming galaxies at 0.07 z 0.14

Dust attenuation in galaxies has been extensively studied nearby, however, there are still many unknowns regarding attenuation in distant galaxies. We contribute to this effort using observations of star-forming galaxies in the redshift range z = 0.05-0.15 from the DYnamics of Newly Assembled Massive Objects (DYNAMO) survey. Highly star-forming DYNAMO galaxies share many similar attributes to clumpy, star-forming galaxies at high redshift. Considering integrated Sloan Digital Sky Survey observations, trends between attenuation and other galaxy properties for DYNAMO galaxies are well matched to star-forming galaxies at high redshift. Integrated gas attenuations of DYNAMO galaxies are 0.2-2.0 mag in the V band and the ratio of E(B - V)stars and E(B - V)gas is 0.78-0.08 (compared to 0.44 at low redshift). Four highly star-forming DYNAMO galaxies were observed at Hα using the Hubble Space Telescope (HST) and at Paα using integral field spectroscopy at Keck. The latter achieve similar resolution (∼0.8-1 kpc) to our HST imaging using adaptive optics, providing resolved observations of gas attenuations of these galaxies on sub-kiloparsec scales. We find <1.0 mag of variation in attenuation (at Hα) from clump to clump, with no evidence of highly attenuated star formation. Attenuations are in the range 0.3-2.2 mag in the V band, consistent with the attenuations of low-redshift star-forming galaxies. The small spatial variation on attenuation suggests that a majority of the star formation activity in these four galaxies occurs in relatively unobscured regions and thus star formation is well characterized by our Hα observations.