Recent star formation in nearby galaxies from GALEX imaging:M101 and M51
  The GALEX (Galaxy Evolution Explorer) Nearby Galaxies Survey is providing deep far-UV and near-UV imaging for a representative sample of galaxies in the local universe. We present early results for M51 and M101, from GALEX UV imaging and SDSS optical data in five bands. The multi-band photometry of compact stellar complexes in M101 is compared to population synthesis models, to derive ages, reddening, reddening-corrected luminosities and current/initial masses. The GALEX UV photometry provides a complete census of young compact complexes on a approximately 160pc scale. A galactocentric gradient of the far-UV - near-UV color indicates younger stellar populations towards the outer parts of the galaxy disks, the effect being more pronounced in M101 than in M51. 
Luciana Bianchi (JHU), D.Thilker, D.Burgarella, P.Friedman, C.Hoopes,   S.Boissier, A.Gil de Paz, T.Barlow, Y.-I.Byun, J.Don...