Segregation effects in DEEP2 galaxy groups
  We investigate segregation phenomena in galaxy groups in the range of
$0.2<z<1$. We study a sample of groups selected from the 4th Data Release of
the DEEP2 galaxy redshift survey. We used only groups with at least 8 members
within a radius of 4$\;$Mpc. Outliers were removed with the shifting gapper
techinque and, then, the virial properties were estimated for each group. The
sample was divided into two stacked systems: low($z\leq0.6$) and high($z>0.6$)
redshift groups. Assuming that the color index ${(U-B)_0}$ can be used as a
proxy for the galaxy type, we found that the fraction of blue (star-forming)
objects is higher in the high-z sample, with blue objects being dominant at
$M_{B}>-19.5$ for both samples, and red objects being dominant at $M_{B}<-19.5$
only for the low-z sample. Also, the radial variation of the red fraction
indicates that there are more red objects with $R<R_{200}$ in the low-z sample
than in the high-z sample. Our analysis indicates statistical evidence of
kinematic segregation, at the 99%c.l., for the low-z sample: redder and
brighter galaxies present lower velocity dispersions than bluer and fainter
ones. We also find a weaker evidence for spatial segregation between red and
blue objects, at the 70%c.l. The analysis of the high-z sample reveals a
different result: red and blue galaxies have velocity dispersion distributions
not statistically distinct, although redder objects are more concentrated than
the bluer ones at the 95%c.l. From the comparison of blue/red and bright/faint
fractions, and considering the approximate lookback timescale between the two
samples ($\sim$3 Gyr), our results are consistent with a scenario where bright
red galaxies had time to reach energy equipartition, while faint blue/red
galaxies in the outskirts infall to the inner parts of the groups, thus
reducing spatial segregation from $z\sim0.8$ to $z\sim0.4$.
