Stellar Masses of Luminous Compact Blue Galaxies at Redshifts z = 0 . 4 −

We present stellar mass measurements for a sample of 36 Luminous Compact Blue Galaxies (LCBGs) at redshifts z = 0.4-1.2 in the Flanking Fields around the Hubble Deep Field North. The technique is based on fitting a two-component galaxy population model to multi-broadband photometry. Best-fit models are found to be largely independent on the assumed values for the IMF and the metallicity of the stellar populations , but are sensitive to the amount of extinction and the extinction law adopted. On average, the best-fit model corresponds to a LMC extinction law with E(B-V)=0.5. Stellar mass estimates, however, are remarkably independent on the final model choice. Using a Salpeter IMF, the derived median stellar mass for this sample is 5 × 10 9 M ⊙ , i.e., ∼2 times smaller than previous virial mass estimates. Despite uncertainties of a factor 2-3, our results strengthen prior claims that L * CBGs at intermediate redshifts are, on average, about 10 times less massive than a typical L * galaxy today.