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Large-Scale Outflows in Edge-on Seyfert Galaxies. III. Kiloparsec-Scale Soft X-ray Emission

Edward J. M. Colbert·Stefi A. Baum·Chris P. O'Dea·Sylvain Veilleux
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Abstract

We present ROSAT PSPC and HRI images of eight galaxies selected from a distance-limited sample of 22 edge-on Seyfert galaxies. Kiloparsec-scale soft X-ray nebulae extend along the galaxy minor axes in three galaxies (NGC 2992, NGC 4388 and NGC 5506). The extended X-ray emission has 0.2-2.4 keV X-ray luminosities of $0.4-3.5 \times 10^{40} erg s^{-1}$. The X-ray nebulae are roughly co-spatial with the large-scale radio emission, suggesting that both are produced by large-scale galactic outflows. Assuming pressure balance between the radio and X-ray plasmas, the X-ray filling factor is $\gapprox 10^4$ times larger than the radio plasma filling factor, suggesting that large-scale outflows in Seyfert galaxies are predominantly winds of thermal X-ray emitting gas. We favor an interpretation in which large-scale outflows originate as AGN-driven jets that entrain and heat gas on kpc scales as they make their way out of the galaxy. AGN- and starburst-driven winds are also possible explanations in cases where the winds are oriented along the rotation axis of the galaxy disk.

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Edward J. M. Colbert, Stefi A. Baum, Chris P. O'Dea, Sylvain Veilleux. 1997-11-12. Large-Scale Outflows in Edge-on Seyfert Galaxies. III. Kiloparsec-Scale Soft X-ray Emission. https://doi.org/10.1086/305417

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