Isophote Shapes of Early-Type Galaxies in Massive Clusters at $z\sim1$
  and 0
  We compare the isophote shape parameter $a_{4}$ of early-type galaxies (ETGs)
between $z\sim1$ and 0 as a proxy for dynamics to investigate the epoch at
which the dynamical properties of ETGs are established, using cluster ETG
samples with stellar masses of $\log(M_{*}/M_{\odot})\geq10.5$ which have
spectroscopic redshifts. We have 130 ETGs from the Hubble Space Telescope
Cluster Supernova Survey for $z\sim1$ and 355 ETGs from the Sloan Digital Sky
Survey for $z\sim0$. We have developed an isophote shape analysis method which
can be used for high-redshift galaxies and has been carefully compared with
published results. We have applied the same method for both the $z\sim1$ and
$0$ samples. We find similar dependence of the $a_{4}$ parameter on the mass
and size at $z\sim1$ and 0; the main population of ETGs changes from disky to
boxy at a critical stellar mass of $\log(M_{*}/M_{\odot})\sim11.5$ with the
massive end dominated by boxy. The disky ETG fraction decreases with increasing
stellar mass both at $z\sim1$ and $0$, and is consistent between these
redshifts in all stellar mass bins when the Eddington bias is taken into
account. Although uncertainties are large, the results suggest that the
isophote shapes and probably dynamical properties of ETGs in massive clusters
are already in place at $z>1$ and do not significantly evolve in $z<1$, despite
significant size evolution in the same galaxy population. The constant disky
fraction favors less violent processes than mergers as a main cause of the size
and morphological evolution of intermediate mass ETGs in $z<1$.
