Activity and quiescence in galaxies at redshifts 1.4<z<3.5. The role of
  the starburst temperature
  We investigate 'activity' and 'quiescence' in galaxies at relatively high
redshifts by modelling the line(and continuum) spectra of each object. The
models account consistently for photoionization and shocks. We claim that the
starburst effective temperature, the flux from an AGN, and the shock velocity
are critical to activity. The results confirm that two sample galaxies show
intense starburst activity with temperatures reaching Ts=2x10^5K and shock
velocities Vs> 250 km/s, while for the remaining galaxies of our sample the
models show quiescent star formation with Ts< 7x10^4K. A Seyfert 2 like AGN is
proposed in one galaxy. The O/H relative abundances derived by the detailed
modelling of the spectra are nearly solar for all the sample galaxies, in
contrast to those obtained by direct methods.
