Highly ionized collimated outflow from HE 0238-1904: Highly ionized outflow

We present a detailed analysis of a highly ionized, multiphased and collimated outflowing gas detected through OV, OVI, NeVIII and Mg X absorption associated with the QSO HE 02381904 (z(em) similar or equal to 0.629). Based on the similarities in the absorption-line profiles and estimated covering fractions, we find that the OVI and Ne VIII absorption trace the same phase of the absorbing gas. Simple photoionization models can reproduce the observed N(Ne VIII), N(O VI) and N(Mg X) from a single phase whereas the low-ionization species (e. g. NIII, NIV and O IV) originate from a different phase. The measured N(Ne VIII)/N(O VI) ratio is found to be remarkably similar (within a factor of similar to 2) in several individual absorption components kinematically spread over similar to 1800 km s(-1). Under photoionization this requires a fine-tuning between hydrogen density (n(H)) and the distance of the absorbing gas from the Quasi Stellar Object (QSO). Alternatively, this can also be explained by collisional ionization in hot gas with T >= 10(5.7) K. Long-term stability favours the absorbing gas being located outside the broad-line region. We speculate that the collimated flow of such a hot gas could possibly be triggered by the radio jet interaction.