Abundance ratios and IMF slope in the dwarf elliptical galaxy NGC~1396
  with MUSE
  Deep observations of the dwarf elliptical (dE) galaxy NGC 1396 (M$_V =
-16.60$, Mass $\sim 4\times10^8$ M$_\odot$), located in the Fornax cluster,
have been performed with the VLT/ MUSE spectrograph in the wavelength region
from $4750-9350$ \AA{}. In this paper we present a stellar population analysis
studying chemical abundances, the star formation history (SFH) and the stellar
initial mass function (IMF) as a function of galacto-centric distance.
Different, independent ways to analyse the stellar populations result in a
luminosity-weighted age of $\sim$ 6 Gyr and a metallicity [Fe/H]$\sim$ $-0.4$,
similar to other dEs of similar mass. We find unusually overabundant values of
[Ca/Fe] $\sim +0.1$, and under-abundant Sodium, with [Na/Fe] values around
$-0.1$, while [Mg/Fe] is overabundant at all radii, increasing from $\sim+0.1$
in the centre to $\sim +0.2$ dex. We notice a significant metallicity and age
gradient within this dwarf galaxy. To constrain the stellar IMF of NGC 1396, we
find that the IMF of NGC 1396 is consistent with either a Kroupa-like or a
top-heavy distribution, while a bottom-heavy IMF is firmly ruled out. An
analysis of the abundance ratios, and a comparison with galaxies in the Local
Group, shows that the chemical enrichment history of NGC 1396 is similar to the
Galactic disc, with an extended star formation history. This would be the case
if the galaxy originated from a LMC-sized dwarf galaxy progenitor, which would
lose its gas while falling into the Fornax cluster.
