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arXiv · 1203.3049

Highly Ionized Collimated Outflow from HE 0238 - 1904

Sowgat Muzahid·Raghunathan Srianand·Blair D. Savage·Anand Narayanan·Vijay Mohan·Gulab C. Dewangan
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Abstract

We present a detailed analysis of a highly ionized, multiphased and collimated outflowing gas detected through O V, O VI, Ne VIII and Mg X absorption associated with the QSO HE 0238 - 1904 (z_em ~ 0.629). Based on the similarities in the absorption line profiles and estimated covering fractions, we find that the O VI 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. N III, N IV, 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 ~ 2) in several individual absorption components kinematically spread over ~ 1800 km/s. Under photoionization this requires a fine tuning between hydrogen density (nH) and the distance of the absorbing gas from the QSO. Alternatively this can also be explained by collisional ionization in hot gas with T > 10^{5.7} K. Long-term stability favors the absorbing gas being located outside the broad line region (BLR). We speculate that the collimated flow of such a hot gas could possibly be triggered by the radio jet interaction.

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Sowgat Muzahid, Raghunathan Srianand, Blair D. Savage, Anand Narayanan, Vijay Mohan, Gulab C. Dewangan. 2012-05-17. Highly Ionized Collimated Outflow from HE 0238 - 1904. https://doi.org/10.1111/j.1745-3933.2012.01288.x

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