NGC 1365: A LOW COLUMN DENSITY STATE UNVEILING A LOW IONIZATION DISK WIND

We present the time-resolved spectral analysis of the XMM-Newton data of NGC 1365 collected during one XMM-Newton observation, which caught this changing-look active galactic nucleus in a high flux state characterized also by a low column density (N-H similar to 10(22) cm(-2)) of the X-ray absorber. During this observation, the low-energy photoelectric cut-off is at about similar to 1 keV and the primary continuum can be investigated with the XMM-Newton-RGS data, which show strong spectral variability that can be explained as a variable low N-H that decreased from N-H similar to 10(23) cm(-2) to 10(22) cm(-2) in a 100 ks timescale. The spectral analysis of the last segment of the observation revealed the presence of several absorption features that can be associated with an ionized (log xi similar to 2 erg cm s(-1)) outflowing wind (upsilon(out) similar to 2000 km s(-1)). We detected for the first time a possible P-Cygni profile of the Mg xII Ly alpha line associated with this mildly ionized absorber indicative of a wide angle outflowing wind. We suggest that this wind is a low ionization zone of the highly ionized wind present in NGC 1365, which is responsible for the iron K absorption lines and is located within the variable X-ray absorber. At the end of the observation, we detected a strong absorption line at E similar to 0.76 keV most likely associated with a lower ionization zone of the absorber (log xi similar to 0.2 erg cm s(-1), N-H similar to 10(22) cm(-2)), which suggests that the variable absorber in NGC 1365 could be a low ionization zone of the disk wind.