  We investigate the physical structure of the AGN wind in the Seyfert-1 galaxy
NGC 7469 through high-resolution X-ray spectroscopy with Chandra HETGS and
photoionisation modelling. Contemporaneous data from Chandra, HST, and Swift
are used to model the optical-UV-X-ray continuum and determine the spectral
energy distribution (SED) at two epochs, 13 years apart. For our investigation
we use new observations taken in December 2015-January 2016, and historical
ones taken in December 2002. We study the impact of a change in the SED shape,
seen between the two epochs, on the photoionisation of the wind. The HETGS
spectroscopy shows that the AGN wind in NGC 7469 consists of four ionisation
components, with their outflow velocities ranging from -400 to -1800 km/s. From
our modelling we find that the change in the ionising continuum shape between
the two epochs results in some variation in the ionisation state of the wind
components. However, for the main ions detected in X-rays, the sum of their
column densities over all four components, remains in practice unchanged. For
two of the four components, which are found to be thermally unstable in both
epochs, we obtain 2 < r < 31 pc and 12 < r < 29 pc using the cooling and
recombination timescales. For the other two thermally stable components, we
obtain r < 31 pc and r < 80 pc from the recombination timescale. The results of
our photoionisation modelling and thermal stability analysis suggest that the
absorber components in NGC 7469 are consistent with being a thermally-driven
wind from the AGN torus. Finally, from analysis of the zeroth-order ACIS/HETG
data, we discover that the X-ray emission between 0.2-1 keV is spatially
extended over 1.5-12". This diffuse soft X-ray emission is explained by coronal
emission from the nuclear starburst ring in NGC 7469.
