We present a kinematic analysis of the globular cluster ( GC ) system in the giant elliptical galaxy ( gE ) NGC 4636 in the Virgo cluster .
Using the photometric and spectroscopic database of 238 GCs ( 108 blue GCs and 130 red GCs ) at the galactocentric radius 0 \arcmin . 39 < R < 15 \arcmin . 43 , we have investigated the kinematics of the GC system .
The NGC 4636 GC system shows weak overall rotation , which is dominated by the red GCs .
However , both the blue GCs and red GCs show some rotation in the inner region at R < 4 \arcmin . 3 ( = 2.9 R _ { eff } = 18.5 kpc ) .
The velocity dispersion for all the GCs is derived to be \sigma _ { p } = 225 ^ { +12 } _ { -9 } km s ^ { -1 } .
The velocity dispersion for the blue GCs ( \sigma _ { p } = 251 ^ { +18 } _ { -12 } km s ^ { -1 } ) is slightly larger than that for the red GCs ( \sigma _ { p } = 205 ^ { +11 } _ { -13 } km s ^ { -1 } ) .
The velocity dispersions for the blue GCs about the mean velocity and about the best fit rotation curve have a significant variation depending on the galactocentric radius .
Comparison of observed stellar and GC velocity dispersion profiles with the velocity dispersion profiles calculated from the stellar mass profile shows that the mass-to-light ratio should increase as the galactocentric distance increases , indicating the existence of an extended dark matter halo .
From the comparison of the observed GC velocity dispersion profiles and the velocity dispersion profiles calculated for the X-ray mass profiles in the literature , we find that the orbit of the GC system is tangential , and that the orbit of the red GCs is slightly more tangential than that of the blue GCs .
We compare the GC kinematics of NGC 4636 with those of other six gEs , finding that the kinematic properties of the GCs are diverse among gEs .
We find several correlations between the kinematics of the GCs and the global parameters of their host galaxies .
We discuss the implication of the results for the formation models of the GC system in gEs , and suggest a mixture scenario for the origin of the GCs in gEs .