| OBSERVATIONS OF THE HAWAII HDF-N FIELD |
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| Velocity offset between Hawaii and TKRS DEIMOS redshifts |
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The accuracy of the redshift determinations may be empirically
determined by comparing the differerent samples. The figure
shows the distribution of dv (TKRS-Hawaii) for
the overlapping sample of 205 galaxies where there are both
TKRS and Hawaii DEIMOS redshifts. The best fit
Gaussian shown gives an offset of -20 km/s
and a sigma of 50 km/s.
19 galaxies have abs(dv) > 180 km/s including
the one totally deviant object discussed above.
The LRIS accuracy is about a factor of 3 poorer. For the full Cohen compilation the offset is -54 km/s and the dispersion is 152 km/s when compared with the Hawaii DEIMOS redshifts. For the Hawaii LRIS I the offset is +80 km/s and the dispersion is 180 km/s (both based on best fit Gaussians to the total distribution). Thus the DEIMOS determinations should be preferred where they are available. |