The X-ray warm absorber and nuclear obscuration in the Seyfert 1.8
  galaxy ESO 113-G010
  We present the first analysis of the X-ray warm absorber and nuclear
obscuration in the Seyfert 1.8 galaxy ESO 113-G010. We used archival data from
a 100 ks XMM-Newton observation made in 2005. From high resolution spectroscopy
analysis of the RGS data, we detect absorption lines originating from a warm
absorber consisting of two distinct phases of ionisation, with log xi ~ 3.2 and
2.3 respectively. The higher-ionised component has a larger column density and
outflow velocity (N_H ~ 1.6 x 10^22 cm^-2, v ~ -1100 km/s) than the
lower-ionised component (N_H ~ 0.5 x 10^22 cm^-2, v ~ -700 km/s). The shape of
the optical-UV continuum and the large Balmer decrement (H_alpha/H_beta ~ 8)
indicate significant amount of reddening is taking place in our line of sight
in the host galaxy of the AGN; however, the X-ray spectrum is not absorbed by
cold neutral gas intrinsic to the source. We discuss different explanations for
this discrepancy between the reddening and the X-ray absorption, and suggest
that the most likely solution is a dusty warm absorber. We show that dust can
exist in the lower-ionised phase of the warm absorber, which causes the
observed reddening of the optical-UV emission, whereas the X-rays remain
unabsorbed due to lack of cold neutral gas in the ionised warm absorber.
Furthermore, we have investigated the uncertainties in the construction of the
Spectral Energy Distribution (SED) of this object due to obscuration of the
nuclear source and the effects this has on the photoionisation modelling of the
warm absorber. We show how the assumed SEDs influence the thermal stability of
each phase and whether or not the two absorber phases in ESO 113-G010 can
co-exist in pressure equilibrium.
