  The HR Del nova remnant was observed with the IFU-GMOS at Gemini North. The
spatially resolved spectral data cube was used in the kinematic, morphological
and abundance analysis of the ejecta. The line maps show a very clumpy shell
with two main symmetric structures. The first one is the outer part of the
shell seen in H-alpha, that forms two rings projected in the sky plane. These
ring structures correspond to a closed hourglass shape, first proposed by
Harman and O'Brien (2003). The equatorial emission enhancement is caused by the
superimposed hourglass structures in the line of sight. The second structure
seen only in the [OIII] and [NII] maps is located along the polar directions
inside the hourglass structure. Abundances gradients between the polar caps and
equatorial region were not found. However, the outer part of the shell seems to
be less abundant in Oxygen and Nitrogen than the inner regions. Detailed 2.5D
photoionization modeling of the 3D shell was performed using the mass
distribution inferred from the observations and the presence of mass clumps.
The resulting model grids are used to constrain the physical properties of the
shell as well as the central ionizing source. A sequence of 3D clumpy models
including a disk shaped ionization source is able to reproduce the ionization
gradients between polar and equatorial regions of the shell. Differences
between shell axial ratios in different lines can also be explained by
aspherical illumination. A total shell mass of 9 x 10-4 Msun is derived from
these models. We estimate that 50% to 70% of the shell mass is contained in
neutral clumps with density contrast up to a factor of 30.
