The parameters of the fitting model were the projected rotation velocity V sin of the galaxian disk in km/s (slit spectra cannot be used to disentangle V and sin ), the [OII] exponential disk scale length in h kpc, the [OII] total line flux in DU and the dimensionless [OII] doublet intensity ratio I(3726 Å)/I(3729 Å). It was necessary to include the doublet intensity ratio in the model to deal with the broadening of the observed [OII] profile resulting from the effect of the (1+z) spectral stretching on the doublet separation. The rest-frame separation of the doublet components is 2.7 Å. The observed separation can only be resolved at redshifts of z 0.40.5 ( = 3.9 Å) with the MOS/SIS spectral resolutions of 35Å. Even though the signal-to-noise ratios and the spectral resolution may not been adequate to measure a precise value for the [OII] ratio, the additional degree of freedom was needed to properly model the observed line profile.

Mon Sep 2 12:37:40 PDT 1996