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 \gtrsim 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 .