The Stellar Mass Content of Submillimeter-Selected Galaxies
  We present a new study of the stellar mass in a sample of ~ 70
submillimeter-selected galaxies (SMGs) with accurate spectroscopic redshifts.
We fit combinations of stellar population synthesis models and power laws to
the galaxies' observed-frame optical through mid-IR spectral energy
distributions to separate stellar emission from non-stellar near-IR continuum.
By separating the stellar emission from the non-stellar near-IR continuum, we
find that ~ 50% of our sample have non-stellar continuum contributions of less
than 10% in rest-frame H-band, but ~ 10% of our sample have non-stellar
contributions greater than 50%. We find that the K-band luminosity of the
non-stellar continuum emission is correlated with hard X-ray luminosity,
indicating an AGN origin of the emission. Upon subtracting this AGN-contributed
continuum component from all of the galaxies in our sample, we determine a
lower median stellar mass for SMGs than previous studies, ~ 7 x 10^10 M_sun. We
use constraints of the starburst time-scale from molecular gas studies to
estimate the amount of fading our sample would undergo if they passively evolve
after the starburst terminates. The results suggest that typical SMGs, while
among the most massive galaxies at z ~ 2, are likely to produce descendants of
similar mass and luminosity to L* galaxies in the local universe.
