Ejm. Colbert et al., LARGE-SCALE OUTFLOWS IN EDGE-ON SEYFERT-GALAXIES - III - KILOPARSEC-SCALE SOFT-X-RAY EMISSION, The Astrophysical journal, 496(2), 1998, pp. 786-796
We present ROSAT PSPC and HRI images of eight galaxies selected from a
distance-limited sample of 22 edge-on Seyfert galaxies. Kiloparsec-sc
ale soft X-ray nebulae extend along the galaxy minor axes in three gal
axies (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 x 10(40) ergs s(-1). The
X-ray nebulae are roughly cospatial with the large-scale radio emissi
on, 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 greater than or similar to 10(4) times larger t
han the radio plasma filling factor, suggesting that large-scale outfl
ows in Seyfert galaxies are predominantly winds of thermal X-ray-emitt
ing gas. We favor an interpretation in which large-scale outflows orig
inate as active galactic nucleus-driven jets that entrain and heat gas
on kiloparsec scales as they make their way out of the galaxy. Active
galactic nucleus-and starburst-driven winds are also possible explana
tions in cases where the winds are oriented along the rotation axis of
the galaxy disk.