Kraemer, S. B.Turner, T. J.Couto, J. D.Crenshaw, D. M.Schmitt, H. R.Revalski, M.Fischer, T. C.2020-03-252020-03-252020-02-14Kraemer, S. B.; Turner, T. J.; Couto, J. D.; Crenshaw, D. M.; Schmitt, H. R.; Revalski, M.; Fischer, T. C.; Mass outflow of the X-ray emission line gas in NGC 4151; Monthly Notices of the Royal Astronomical Society 493(3), pages 3893-3910 (2020); https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/staa428/5736047https://doi.org/10.1093/mnras/staa428http://hdl.handle.net/11603/17639We have analysed Chandra/High Energy Transmission Gratings spectra of the X-ray emission line gas in the Seyfert galaxy NGC 4151. The zeroth-order spectral images show extended H- and He-like O and Ne, up to a distance r ∼ 200 pc from the nucleus. Using the first-order spectra, we measure an average line velocity ∼−230 km s⁻¹, suggesting significant outflow of X-ray gas. We generated CLOUDY photoionization models to fit the first-order spectra; the fit required three distinct emission line components. To estimate the total mass of ionized gas and the mass outflow rates, we applied the model parameters to fit the zeroth-order emission line profiles of Ne IX and Ne X. We determined the total mass of ≈5.4 × 10⁵ M⊙. Assuming the same kinematic profile as that for the [O III] gas, derived from our analysis of Hubble Space Telescope/Space Telescope Imaging Spectrograph spectra, the peak X-ray mass outflow rate was ≈1.8 M⊙ yr⁻¹, at r ∼ 150 pc. The total mass and mass outflow rates are similar to those determined using [O III], implying that the X-ray gas is a major outflow component. However, unlike the optical outflows, the X-ray outflow rate does not drop off at r > 100 pc, which suggests that it may have a greater impact on the host galaxy.18 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical SocietyText