  In this paper we test the idea that the low-metallicity hot gas in the centre
of NGC 1291 is heated via a dynamical process. In this scenario, the gas from
the outer gas-rich ring loses energy through bar-driven shocks and falls to the
centre. Heating of the gas to X-ray temperatures comes from the high velocity
that it reaches ($\approx$ 700 \kms) as it falls to the bottom of the potential
well. This would explain why the stellar metallicity in the bulge region is
around solar while the hot gas metallicity is around 0.1 solar. We carried out
an observational test to check this hypothesis by measuring the metallicity of
HII regions in the outer ring to check whether they matched the hot gas
metallicity. For this purpose we obtained medium resolution long slit
spectroscopy with FORS1 on the ESO VLT at Paranal and obtained the
metallicities using emission line ratio diagnostics. The obtained metallicities
are compatible with the bulge stellar metallicities but very different from the
hot-gas metallicity. However, when comparing the different time-scales, the gas
in the ring had time enough to get enriched through stellar processes,
therefore we cannot rule out the dynamical mechanism as the heating process of
the gas. However, the blue colours of the outer ring and the dust structures in
the bar region could suggest that the origin of the X-ray hot gas is due to the
infall of material from further out.
