  The distribution of metals in groups of galaxies holds important information
about the chemical enrichment history of the Universe. Here we present radial
profiles of temperature and the abundance of iron and silicon of the hot
intragroup medium for a sample of 15 nearby groups of galaxies observed by
Chandra, selected for their regular X-ray morphology. All but one group display
a cool core, the size of which is found to correlate with the mean temperature
of the group derived outside this core. When scaled to this mean temperature,
the temperature profiles are remarkably similar, being analogous to those of
more massive clusters at large radii but significantly flatter inwards of the
temperature peak. The Fe abundance generally shows a central excess followed by
a radial decline, reaching a typical value of 0.1 solar within r_500, a factor
of two lower than corresponding results for clusters. Si shows less systematic
radial variation, on average displaying a less pronounced decline than Fe and
showing evidence for a flattening at large radii. Off-centre abundance peaks
are seen both for Fe and Si in a number of groups with well-resolved cores.
Derived abundance ratios indicate that supernovae type Ia are responsible for
80 per cent of the Fe in the group core, but the type II contribution increases
with radius and completely dominates at r_500. We present fitting formulae for
the radial dependence of temperature and abundances, to facilitate comparison
to results of numerical simulations of group formation and evolution. In a
companion paper, we discuss the implications of these results for feedback and
enrichment in galaxy groups.
