  We present the observation of the Tycho supernova remnant obtained with the
EPIC and RGS instruments onboard the XMM-Newton satellite. We compare images
and azimuthally averaged radial profiles in emission lines from different
elements (silicon and iron) and different transition lines of iron (Fe L and Fe
K). While the Fe XVII L line and Si XIII K line images are globally spatially
coincident, the Fe K emission clearly peaks at a smaller radius, indicating a
higher temperature toward the reverse shock. This is qualitatively the profile
expected when the reverse shock, after travelling through the outer power-law
density profile, has entered the central plateau of the ejecta. The high energy
continuum map has an overall smooth distribution, with a similar extent to the
radio emission. Its radial profile peaks further out than the lines emission.
Brighter and harder continuum regions are observed with a rough bipolar
symmetry in the eastern and western edges. The spectral analysis of the
southeastern knots supports spatial variations of the relative abundance of
silicon and iron, which implies an incomplete mixing of the silicon and iron
layers.
