  In this work we analyze the physical properties of a sample of 153 star
forming galaxies at z~0.84, selected by their H-alpha flux with a NB filter.
B-band luminosities of the objects are higher than those of local star forming
galaxies. Most of the galaxies are located in the blue cloud, though some
objects are detected in the green valley and in the red sequence. After the
extinction correction is applied virtually all these red galaxies move to the
blue sequence, unveiling their dusty nature. A check on the extinction law
reveals that the typical extinction law for local starbursts is well suited for
our sample but with E(B-V)_stars=0.55 E(B-V)_gas. We compare star formation
rates (SFR) measured with different tracers (H-alpha, UV and IR) finding that
they agree within a factor of three after extinction correction. We find a
correlation between the ratios SFR_FUV/SFR_H-alpha, SFR_IR/SFR_H-alpha and the
EW(H-alpha) (i.e. weighted age) which accounts for part of the scatter. We
obtain stellar mass estimations fitting templates to multi-wavelength
photometry. The typical stellar mass of a galaxy within our sample is ~10^10
Msun. The SFR is correlated with stellar mass and the specific star formation
rate (sSFR) decreases with it, indicating that massive galaxies are less
affected by star formation processes than less massive ones. This result is
consistent with the downsizing scenario. To quantify this downsizing we
estimated the quenching mass M_Q for our sample at z~0.84, finding that it
declines from M_Q ~10^12 Msun to M_Q ~8x10^10 Msun at the local Universe.

Cosmology and Nongalactic Astrophysics