Investigating the complex absorbers of Mrk 766 with XMM-Newton

Aims. We examine the high energy resolution X-ray spectrum of the narrow-line Seyfert 1 galaxy Mrk 766 using 4 observations taken with XMM-Newton in 2005, to investigate the properties of the complex ionised absorber / emitter along the line of sight, as well as absorption by dust intrinsic to the source. Methods. We make use of the high-energy resolution RGS spectrum to infer the properties of the intervening matter. We also use the spectrum obtained by EPIC-pn and the photometric measurements of OM to obtain the spectral energy distribution of the source, necessary for the photoionisation modelling of the ionised outflow. Results. The warm absorber in Mrk 766 consists of two phases of photoionisation. In addition to these two warm absorber components with $\log\xi\sim 2.15$ and $\log\xi\sim -0.58$, we find evidence of absorption by a collisionally ionised component ($T\sim51$ eV). We discuss the implication of this additional component in light of theoretical predictions. Moreover, we detect signs of absorption by a dusty medium with $N_\text{dust}\sim 7.29\times 10^{16}$ cm$^{-2}$. Finally the relatively weak emission features in the spectrum seem to be unrelated to the absorbers and probably originated by an out-of sight-line ionised plasma.