  The Coma cluster was observed with an X-ray Imaging Spectrometer (XIS)
onboard Suzaku in six pointings, including the central X-ray peak region, the
14'west offset region, 30'and 34'north-west offset regions, and 44'and
60'south-west offset regions. Owing to its lower background level, Suzaku has
better sensitivity to Fe K-alpha lines than other satellites. Using precise Fe
line measurements, we studied the temperature structure, possible bulk motions,
and iron abundance distributions in the intracluster medium (ICM). The observed
spectra were well-represented by a single-temperature model, and two- or three-
temperature model did not improve chi-square substantially. The temperature,
derived from K-alpha line ratios of H-like and He-like Fe, agree with those
derived from the single-temperature model. Because the line ratio is a steep
function of temperature, the consistency supports the accuracy of temperature
measurements conducted with Suzaku. Within the 34'region, the redshift derived
from the central energy of the He-like Fe line is consistent with that from
optical observations, within a calibration error of 18 eV or 818 km/s in the
line of sight. This value is smaller than the sound velocity of ICM, which is
1500 km/s. The central energy of Fe lines at the 44'offset region around the
NGC 4839 subcluster is also consistent with those within the 34'region. These
results on the temperature and velocity structure suggest that the core of the
cluster is in a relaxed state, and non-thermal electrons relevant to the radio
halo are accelerated by intracluster turbulence rather than large-scale shocks.
Fe abundance is almost constant at 0.4 solar within the 34'region, and
decreases with radius. This value is slightly lower than those of other
clusters, which means the gas have been mixed well during a past merger
associated with the growth of the cluster.
