Mapping dust-obscured light in califa galaxies

The Calar Alto Legacy Integral Field Area (CALIFA) survey is the first and largest survey of its kind, aiming to obtain optical datacubes for 600 nearby (z ∼ 0.01) galaxies. Over 300 objects have already been observed. The spatial and spectral resolutions in CAL-IFA, combined with its sample size, offer unprecedented good quality data to study spatially resolved dust properties. This work focus on how dust is mapped by the ionised gas. By carefully removing the underlying stellar population, we measure the emissionline Balmer decrement (Hα/Hβ) in different regions in galaxies, separating H ii complexes from diffuse emission. We show that the effective dust attenuation measured on an integrated spectrum is underestimated with respect to the effective attenuation on H ii regions. This implies that star formation indicators based on optical and UV data should be used with care and may need to be corrected by differential dust attenuation