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arXiv · 2002.05806

Mass Outflow of the X-ray Emission Line Gas in NGC 4151

S. B. Kraemer·T. J. Turner·J. D. Couto·D. M. Crenshaw·H. R. Schmitt·M. Revalski·T. C. Fischer
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Abstract

We 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 $r \sim$ 200 pc from the nucleus. Using the 1st order spectra, we measure an average line velocity $\sim -230$ km s$^{-1}$, suggesting significant outflow of X-ray gas. We generated Cloudy photoionisation models to fit the 1st order spectra. We required three emission-line components, with column density, log$N_{H}$, and ionisation parameter, log$U$, of 22.5/1.0, 22.5/0.19, and 23.0/-0.50, respectively. To estimate the total mass of ionised 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 $\approx 5.4 \times$ 10$^{5}$ M_sun. Assuming the same kinematic profile as that for the [O~III] gas, the peak X-ray mass outflow rate was $\approx 1.8$ M_sun yr$^{-1}$, at $r \sim 150$ 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.

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S. B. Kraemer, T. J. Turner, J. D. Couto, D. M. Crenshaw, H. R. Schmitt, M. Revalski, T. C. Fischer. 2020-02-13. Mass Outflow of the X-ray Emission Line Gas in NGC 4151. https://doi.org/10.1093/mnras/staa428

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